@c -*- coding: utf-8; mode: texinfo; -*-
@ignore
    Translation of GIT committish: FILL-IN-HEAD-COMMITTISH

    When revising a translation, copy the HEAD committish of the
    version that you are working on.  For details, see the Contributors'
    Guide, node Updating translation committishes..
@end ignore

@include included/acknowledge.itexi
@include included/authors.itexi
@include included/helpus.itexi

@node Community
@unnumbered Community

@divClass{link-headings}

@divClass{column-center-top}
@subheading Interacting with the community

@itemize

@item
@ref{Contact}: get help, discuss, and keep in touch!

@item
@ref{Tiny examples}: these are @emph{highly} recommended when
discussing LilyPond.

@item
@ref{Bug reports}: something went wrong.

@end itemize
@divEnd

@divClass{column-left-bottom}
@subheading Making LilyPond better

@itemize

@item
@ref{Help us}: your assistance is requested.

@item
@ref{Sponsoring}: financial contributions.

@item
@ref{Development}: for contributors and testers.

@item
@ref{Google Summer of Code}: ideas for Google Summer of Code (GSoC).

@item
@ref{Authors}: the people who made LilyPond what it is today.

@item
@ref{Acknowledgements}: projects and institutions that support LilyPond

@end itemize
@divEnd

@divClass{column-right-bottom}
@subheading Miscellaneous

@itemize

@item
@ref{Publications}: what we wrote, and have had written about us.

@item
@ref{News}: news from the LilyPond project.

@item
@ref{Attic}: announcements and changelogs from past versions.

@end itemize
@divEnd

@divEnd

@divClass{hide}
@menu
* Contact::
* Tiny examples::
* Bug reports::
* Help us::
* Sponsoring::
* Development::
* Google Summer of Code::
* Authors::
* Acknowledgements::
* Publications::
* News::
* Attic::
@end menu
@divEnd


@node Contact
@unnumberedsec Contact


@divClass{column-left-bottom}
@subheading User Discussions and Help

@subsubheading User mailing list: @code{lilypond-user@@gnu.org}

This mailing list is the main place for users to discuss and help
each other.

@quotation
@uref{http://lists.gnu.org/mailman/listinfo/lilypond-user,
lilypond-user subscribe and info}

@uref{http://lists.gnu.org/archive/html/lilypond-user/,
user archive1}
@uref{http://www.mail-archive.com/lilypond-user@@gnu.org/,
archive2}
@uref{http://dir.gmane.org/gmane.comp.gnu.lilypond.general,
archive3}

@uref{http://post.gmane.org/post.php?group=gmane.comp.gnu.lilypond.general,
send to lilypond-user with gmane}
@end quotation

@warning{When asking questions, please use @ref{Tiny examples}!}

@subsubheading LilyPond Snippet Repository

The LilyPond Snippet Repository is a large collection of
user-submitted examples, which can freely be copied and used
in your own works.  See what other people have written,
and add your own!

@example
@uref{http://lsr.di.unimi.it}
@end example

Particularly instructive examples from LSR are included in our
official documentation, in @ref{Snippets}.


@subsubheading IRC

Some level of support is provided on our IRC channel,

@example
@uref{irc://irc.freenode.net/lilypond, #lilypond@@irc.freenode.net}
@end example

This channel has no public archive, so any question that may
be useful for others would better be posted to one of the mailing lists.

@html
<form action="http://webchat.freenode.net"
      method="get"
      name="f_lily_irc"
  <label>irc name:
    <input name="nick" type="text" size="15" value="">
  </label>
  <input name="channels" type="hidden" value="lilypond">
  <input type="submit" value="Join #lilypond IRC Chat">
</form>

<script language="JavaScript" type="text/javascript">
  var username = "web";
  var lang = window.navigator.userLanguage ? window.navigator.userLanguage
  : window.navigator.language;
  username += '-' + lang.substr(0, 2);
  username += '-' + navigator.appName.substr(0, 2);
  username += navigator.appCodeName.replace (" ", "").substr(0, 2);
  username += navigator.platform.replace (" ", "").replace("nux", "").replace("n32", "");
  document.forms["f_lily_irc"].nick.value = username;
</script>
@end html

@subsubheading Other languages

@quotation
@uref{http://lists.gnu.org/mailman/listinfo/lilypond-user-fr,
French mailing list}

@uref{http://www.lilypondforum.de/,
German forum}

@uref{http://groups.google.com/group/lilypond-brasil,
Portuguese group}

@uref{http://lists.gnu.org/mailman/listinfo/lilypond-es,
Spanish mailing list}
@end quotation
@divEnd


@divClass{column-right-top}
@subheading The LilyPond Blog

Read our community blog, @q{Scores of Beauty}:

@example
@uref{http://lilypondblog.org}
@end example

@subsubheading Releases mailing list: @code{info-lilypond@@gnu.org}

This mailing list is a low-volume, read-only list which receives
notifications of new releases.

@quotation
@uref{http://lists.gnu.org/mailman/listinfo/info-lilypond,
info-lilypond subscribe and info}

@uref{http://lists.gnu.org/archive/html/info-lilypond/,
info archive1}
@uref{http://www.mail-archive.com/info-lilypond@@gnu.org/,
archive2}
@uref{http://dir.gmane.org/gmane.comp.gnu.lilypond.announce,
archive3}

@c don't include gmane posting here.  -gp
@end quotation


@divEnd


@divClass{column-right-bottom}
@subheading Developer Discussions and Translations

@subsubheading Developer mailing list: @code{lilypond-devel@@gnu.org}

Developer discussions take place on this list. Patches can also be sent
here.

@quotation
@uref{http://lists.gnu.org/mailman/listinfo/lilypond-devel,
lilypond-devel subscribe and info}

@uref{http://lists.gnu.org/archive/html/lilypond-devel/,
devel archive1}
@uref{http://www.mail-archive.com/lilypond-devel@@gnu.org/,
archive2}
@uref{http://dir.gmane.org/gmane.comp.gnu.lilypond.devel,
archive3}

@uref{http://post.gmane.org/post.php?group=gmane.comp.gnu.lilypond.devel,
send to lilypond-devel with gmane}
@end quotation


@subsubheading Bug mailing list: @code{bug-lilypond@@gnu.org}

Bug reports and discussions should be sent here.  Do not send patches
to this list.

@quotation
@uref{http://lists.gnu.org/mailman/listinfo/bug-lilypond,
bug-lilypond subscribe and info}

@uref{http://lists.gnu.org/archive/html/bug-lilypond/,
bug archive1}
@uref{http://www.mail-archive.com/bug-lilypond@@gnu.org/,
archive2}
@uref{http://dir.gmane.org/gmane.comp.gnu.lilypond.bugs,
archive3}

@c don't include gmane posting here.  -gp
@end quotation

@warning{Before sending a message to the bug list, please read our
guidelines for @ref{Bug reports}.}


@subsubheading Translation mailing list: @code{translations@@lilynet.org}

All discussions about translating LilyPond manuals should be sent here.
Do not send patches to this list.

@quotation
@uref{http://lilypond-translations.3384276.n2.nabble.com/,
Translation mailing list archive}
@end quotation

@divEnd


@node Tiny examples
@unnumberedsec Tiny examples

@divClass{column-center-top}
@subheading What are @qq{Tiny examples}?

A tiny example is an example from which @strong{nothing} can be removed.
@divEnd

@divClass{column-left-bottom}
@subheading Why create them?

@divClass{keep-bullets}
@itemize

@item
The simpler the example is, the quicker potential helpers can
understand it and help you.

@item
A tiny example demonstrates that you have put effort towards
solving the problem yourself.  When people send huge portions of
input, it looks like they don't care if we help them or not.

@item
Creating a tiny example helps you to understand what is
happening.  Many false problem reports can be avoided by
attempting to create a tiny example; if you cannot replicate a
@qq{bug} in a tiny example, then the problem was probably an
insufficient understanding of LilyPond, not an actual bug!

@end itemize
@divEnd

@divEnd


@divClass{column-right-bottom}
@subheading How to create them?

@divClass{keep-bullets}
@itemize

@item
Include the @code{\version} number.

@item
Make it small!  Examples about spacing or page layout might
require many bars of music, but most issues can be reproduced
using less than a single measure.

@item
When trying to create an example, try commenting out @w{(@code{%}
or @code{%@{ @dots{} %@}})} sections of your file.  If you
can comment something while still demonstrating the main idea,
then remove the commented-material.

@item
Avoid using complicated notes, keys or time signatures, unless
the bug is about the behavior of those items.

@item
Do not use @code{\override} or @code{\set} commands unless the bug
is about those specific commands.

@item
Optionally, attach an image showing the desired graphical output.

@end itemize
@divEnd

@divEnd

@divClass{column-center-bottom}
@subheading How tiny should they be?

Is the code below a minimal example?

@example
\version "2.14.1"
\include "english.ly"

\score @{
  \new Staff @{
    \key d \major
    \numericTimeSignature
    \time 2/4
    <cs' d'' b''>16 <cs' d'' b''>8.
    %% Here: the tie on the D's looks funny
    %% Too tall? Left-hand endpoint is not aligned with the B tie?
    ~
    <cs' d'' b''>8 [ <b d'' a''> ]
  @}
@}
@end example

Well, it is not very big, but a truly minimal example is here:

@example
\version "2.14.1"
@{
  % middle tie looks funny here:
  <c' d'' b''>8. ~ <c' d'' b''>8
@}
@end example

Very few tiny examples exceed 10 lines of code -
quite often 4 lines are enough to demonstrate the problem!

@divEnd


@node Bug reports
@unnumberedsec Bug reports


@divClass{heading-center}
If you have input that results in a crash or wrong output,
then that is a bug.
@divEnd

@divClass{column-center-top}
@subheading Step 1: Known bugs

We may already know about this bug.  Check here:

@example
@uref{http://sourceforge.net/p/testlilyissues/issues/}
@end example

@warning{Please @strong{DO NOT} add bug reports directly to the
bug tracker.  Once an issue has been added to the tracker, feel
free to add more information to that report.}

@divEnd


@divClass{column-left-bottom}
@subheading Step 2: Creating a bug report

If you have discovered a bug which is not listed,
please help us by creating a bug report.

@warning{We only accept reports in the form of
@ref{Tiny examples}.  We have very limited resources,
so any non-minimal example will be rejected.  Almost
every bug can be demonstrated in four notes or less!}

Here is an example of a good bug report:

@example
% Accidentals should be printed for only
% the first note in a tie, but this version
% prints flats on both notes.
\version "2.10.1"

\relative c'' @{
 bes1 ~
 bes1
@}
@end example

@divEnd

@divClass{column-right-bottom}
@subheading Step 3: Sending a bug report

Once you have verified that the issue is not already known and
created a bug report, please send it to us!

@divClass{keep-bullets}
@itemize

@item
If you are subscribed to the @uref{mailto:bug-lilypond@@gnu.org,
bug-lilypond@@gnu.org} mailing list, send an email like normal.

@item
If you are not subscribed, you can still post a bug report with
the
@uref{http://post.gmane.org/post.php?group=gmane.comp.gnu.lilypond.bugs,
gmane lilypond.bugs web interface}.

However, there is a strict @qq{no top-posting} check on the gmane
interface, which is often incorrectly triggered by lilypond files.
To avoid this, please add:

@example
> I'm not top posting.
@end example

@noindent
(you @emph{must} include the @code{>} ) to the top of your bug
report.

@end itemize
@divEnd
@divEnd

@divClass{column-center-bottom}
@subheading Step 4: Wait for a response

Once your bug report has been sent to the list, our Bug Squad will
examine it; they may ask you for more information.  You will be notified
when the report will be added to the bug tracker.  Please allow up to 4
days, as we have a limited number of volunteers for this task.

Once a bug has been added to the tracker, you can comment it to add
more information about it.
In order to be automatically notified about any activity on the
tracker issue, you may subscribe by clicking the envelope
symbol next to the issue title.
Commenting and subscribing require being logged in with a sourceforge account.
@divEnd

@divClass{column-center-bottom}
@subheading Optional help: show the desired behavior

Once an issue has been added to the tracker, it can be very
helpful if we can see the desired output.  Feel free to add input
code and/or images (possibly created with other tools) which
demonstrate what you think it should look like!

@divEnd



@node Help us
@unnumberedsec Help us

@divClass{column-center-top}
@helpusNeed

@divEnd

@divClass{column-left-top}
@divClass{keep-bullets}
@helpusSimple

@divEnd
@divEnd

@divClass{column-right-top}
@helpusAdvanced

@divEnd


@node Sponsoring
@unnumberedsec Sponsoring

@divClass{keep-bullets}
@divClass{column-left-top}
@subheading Bounties

In the past,

@itemize
@item some users have paid for new features
@item some developers have added new features for hire
@end itemize

The LilyPond project does not organize such efforts; we neither
endorse nor discourage such agreements.  Any contracts between
private individuals is the business of those individuals, not
ours.

@divEnd

@divClass{column-right-top}
@subheading Guidelines

Any user wanting to offer money in exchange for work should bear
in mind the following points:

@itemize
@item
LilyPond developers may advertise their services on the lilypond
email lists from time to time.

@item
Any agreements between private individuals should include the
normal precautions when conducting business: who pays, how much do
they pay, with what method of payment, and upon what set of
conditions.  We suggest that any ambiguity or uncertainty in these
questions should be resolved before any work begins.

@end itemize

@divEnd

@divClass{column-center-bottom}
@subheading Interested developers

Here is a list of people who have expressed an interest in
bounties.  Note that the amount of work done by individuals varies
quite a bit throughout the years.  We do not guarantee that this
list is up-to-date, nor do we guarantee that the people listed
here have any ability.  The only criteria is "XYZ asked to be
listed on this page".

Looking at the git history is a good way to determine who the most
active and experienced developers are.  Statistics up to version
@versionDevel{}:

@multitable @columnfractions .3 .3 .3
@item @uref{http://lilypond.org/~graham/gitstats-all/, overall history}
@tab @uref{http://lilypond.org/~graham/gitstats-1year/, past year}
@tab @uref{http://lilypond.org/~graham/gitstats-3months/, past three months}
@end multitable

Interested developers:
@table @asis
@item @email{lilypond-devel@@gnu.org, LilyPond developer list}
Since no developer currently is listed for commercial development,
your best bet is asking on the developer list.

@c Format
@c @item @email{name@@adress.domain, Name}
@c area of interest (256 chars max)

@end table

@divEnd
@divEnd


@node Development
@unnumberedsec Development

@divClass{heading-center}
@ifclear web_version
  @heading Development for LilyPond @version
@end ifclear
@ifset web_version
  @heading Development for LilyPond @versionDevel
@end ifset


@c we normally don't allow named references, but in this case
@c it's good to emphasize the "stable" part.  -gp
@warning{These are @emph{unstable development} versions.  If you
have the slightest doubt about how to use or install LilyPond, we
urge you to use the @ref{Download, stable Download}, and read the
@ref{Manuals, stable Manuals}.}

@divEnd

@divClass{column-center-top}
@subheading Release numbers

There are two sets of releases for LilyPond: stable releases, and
unstable development releases.  Stable versions have an
even-numbered @q{minor} version number (e.g., 2.8, 2.10, 2.12).
Development versions have an odd-numbered @q{minor} version number
(e.g., 2.7, 2.9, 2.11).

@divEnd


@divClass{column-left-top}
@subheading Download

Instructions for git and compiling are in the Contributor's Guide.

@quotation
@uref{http://git.sv.gnu.org/gitweb/?p=lilypond.git, lilypond git repository}
@end quotation

Documentation writers and testers will generally want to download
the latest binary:

@quotation

@downloadDevelLinuxNormal

@downloadDevelLinuxBig

@downloadDevelLinuxPPC

@downloadDevelFreeBSDNormal

@downloadDevelFreeBSDBig

@downloadDevelDarwinNormal

@downloadDevelDarwinPPC

@downloadDevelWindows

@downloadDevelSource

@end quotation

@divEnd


@divClass{column-right-top}
@subheading Contributor's Guide

LilyPond development is a fairly complicated matter.  In order to
help new contributors, and to keep the whole system (mostly)
stable, we have written a manual for development tasks.

@docLinksBare{Contributor's Guide, contributor,
  @rcontribnamed{Top,Contributor's Guide},
  @manualDevelContributorSplit,
  @manualDevelContributorBig, 500 kB,
  @manualDevelContributorPdf, 2.8 MB}

@divEnd


@divClass{column-center-top}
@subheading Regression tests

@divClass{keep-bullets}

@ifclear web_version

@itemize
@item
@uref{../../input/regression/collated-files.html, Regression tests}:
This release's regtests.
(@uref{../../input/regression/collated-files.pdf, pdf version})

@item
@uref{../../input/regression/musicxml/collated-files.html, MusicXML tests}:
This release's musicXML tests.
(@uref{../../input/regression/musicxml/collated-files.pdf, pdf version})

@item
@uref{../../input/regression/abc2ly/collated-files.html, abc2ly tests}:
This release's abc2ly tests.
(@uref{../../input/regression/abc2ly/collated-files.pdf, pdf version})

@item
@uref{../../input/regression/lilypond-book/collated-files.html, lilypond-book tests}:
This release's lilypond-book tests.
(@uref{../../input/regression/lilypond-book/collated-files.pdf, pdf version})
@end itemize

@end ifclear

@ifset web_version
@subsubheading Development version

@itemize
@item @regtestDevel (@regtestDevelPdf{})

@item @regtestDevelXml (@regtestDevelXmlPdf{})

@item @regtestDevelAbc (@regtestDevelAbcPdf{})

@item @regtestDevelLilypondBook (@regtestDevelLilypondBookPdf{})
@end itemize

@subsubheading Stable version

@itemize
@item @regtestStable (@regtestStablePdf{})

@item @regtestStableXml (@regtestStableXmlPdf{})

@item @regtestStableAbc (@regtestStableAbcPdf{})

@item @regtestStableLilypondBook (@regtestStableLilypondBookPdf{})
@end itemize
@end ifset


@subsubheading All versions

@itemize
@item @uref{http://lilypond.org/test, Comparisons between regression tests}

@item @uref{http://lilypond.org/downloads/binaries/test-output/,
Archive of all regression tests}

@end itemize

@divEnd
@divEnd



@divClass{column-center-bottom}
@subheading Manuals

@ifclear web_version
@warning{These manuals are for LilyPond @version{}; the latest
manuals can be found at @url{http://lilypond.org}}
@end ifclear

@divClass{normal-table}
@multitable @columnfractions .3 .3 .3
@headitem Introduction

@item
@docLinkSplit{Learning,learning,@manualDevelLearningSplit}
@tab
@docLinkBig{Learning,learning,@manualDevelLearningBig}
@tab
@docLinkPdf{Learning,learning,@manualDevelLearningPdf}

@item
@docLinkSplit{Glossary,music-glossary,@manualDevelGlossarySplit}
@tab
@docLinkBig{Glossary,music-glossary,@manualDevelGlossaryBig}
@tab
@docLinkPdf{Glossary,music-glossary,@manualDevelGlossaryPdf}

@item
@docLinkSplit{Essay,essay,@manualDevelEssaySplit}
@tab
@docLinkBig{Essay,essay,@manualDevelEssayBig}
@tab
@docLinkPdf{Essay,essay,@manualDevelEssayPdf}
@end multitable

@multitable @columnfractions .3 .3 .3
@headitem Regular

@item
@docLinkSplit{Notation,notation,@manualDevelNotationSplit}
@tab
@docLinkBig{Notation,notation,@manualDevelNotationBig}
@tab
@docLinkPdf{Notation,notation,@manualDevelNotationPdf}

@item
@docLinkSplit{Usage,usage,@manualDevelUsageSplit}
@tab
@docLinkBig{Usage,usage,@manualDevelUsageBig}
@tab
@docLinkPdf{Usage,usage,@manualDevelUsagePdf}

@item
@docLinkSplit{Snippets,snippets,@manualDevelSnippetsSplit}
@tab
@docLinkBig{Snippets,snippets,@manualDevelSnippetsBig}
@tab
@docLinkPdf{Snippets,snippets,@manualDevelSnippetsPdf}
@end multitable

@multitable @columnfractions .3 .3 .3
@headitem Infrequent

@item
@docLinkSplit{Web,web,@manualDevelWebSplit}
@tab
@docLinkBig{Web,web,@manualDevelWebBig}
@tab
@docLinkPdf{Web,web,@manualDevelWebPdf}

@item
@docLinkSplit{Changes,changes,@manualDevelChangesSplit}
@tab
@docLinkBig{Changes,changes,@manualDevelChangesBig}
@tab
@docLinkPdf{Changes,changes,@manualDevelChangesPdf}

@item
@docLinkSplit{Extending,extending,@manualDevelExtendingSplit}
@tab
@docLinkBig{Extending,extending,@manualDevelExtendingBig}
@tab
@docLinkPdf{Extending,extending,@manualDevelExtendingPdf}

@item
@docLinkSplit{Internals,internals,@manualDevelInternalsSplit}
@tab
@docLinkBig{Internals,internals,@manualDevelInternalsBig}
@tab
@docLinkPdf{Internals,internals,@manualDevelInternalsPdf}
@end multitable

@ifset web_version
@multitable @columnfractions .3
@headitem Downloadable

@item
@doctarballDevel
@end multitable
@end ifset


@divEnd
@divEnd




@node Google Summer of Code
@unnumberedsec Google Summer of Code

@divClass{column-center-top}
@subheading What is Google Summer of Code?

@uref{https://developers.google.com/open-source/gsoc/, GSoC} is a global
program that offers students stipends to write code for free software
and open source projects during the summer.  It is an excellent
opportunity for students to gain experience with real-world software
development and make a contribution that benefits everyone.  It brings
new contributors to LilyPond and enables students who are already
involved to become more involved.  LilyPond participates in GSoC as part
of the @uref{http://www.gnu.org/, GNU project}.

We have had GSoC participants in 2012, 2015 and 2016 and encourage students
to apply for future summers.

If you have questions or would like to apply, send us an email on our
developer mailing list (see @ref{Contact}).

@divEnd

@divClass{column-center-middle-color2}
@subheading Project Ideas List

Below is a list of suggested projects for GSoC or for anyone who is
interested in helping to improve LilyPond. (Last updated: November 2016)

Mentor availability varies from project to project and from year to year.
Send us an email on our developer mailing list (see @ref{Contact}), and
we will help you find a mentor for a project that fits your interests
and skills.

If you have ideas for a GSoC project that is not listed below you can
send us an email as well.  There are a number of areas where LilyPond
could be improved, and our development team is always willing to help
those who would like to tackle a project like those listed below.

A full list of all the current open issues can be found
@uref{http://sourceforge.net/p/testlilyissues/issues/, here}.

@divEnd

@divClass{column-center-middle-color3}
@subheading Improve internal chord structure

The internal representation of LilyPond chords is not powerful enough
to capture the nomenclature of jazz chords.  Currently the chord has
a root, a bass and an inversion.  It would be nice to be able to handle
stacked or polychords, minor/major, etc.  In order to do this, an
internal representation with the ability to capture the essence of
complex chords must be developed.  As a bonus, once the internal
representation is developed, the output formatting of chord names can
be improved.

@strong{Difficulty:} Easy/medium
@strong{Requirements:} Scheme (Guile), but the level necessary can be
easily learned
@strong{Recommended:} Chord theory and naming
@strong{Mentor:} Carl Sorensen

@divEnd

@divClass{column-center-middle-color3}
@subheading Adopt the SMuFL music font encoding standard

For several years now a new standard for music fonts has been around:
@uref{http://www.smufl.org/, SMuFL}, which is also discussed as becoming part of
a future W3C standard for music encoding.  As a FLOSS tool LilyPond should
adhere to such an open standard instead of using an isolated solution like it
does today.  Adopting SMuFL will help integrating LilyPond with the world of
music notation software and eventually give LilyPond users access to a wider
selection of notation fonts.

Making LilyPond compliant to SMuFL includes remapping of the glyphs that are
built from METAFONT sources, adjusting the glyphs' metrics to SMuFL's
specifications, and finally updating the way LilyPond looks up and positions the
glyphs.  As an optional part of this project LilyPond's font loading mechanism
could be modified to use notation fonts installed as system fonts instead of
inside the LilyPond installation.

@strong{Difficulty:} Easy/medium
@strong{Requirements:} C++ and willingness to get familiar with LilyPond
internals.
@strong{Recommended:} Interest and experience in working with font files.
A little bit of METAFONT.
@strong{Mentors:} Werner Lemberg, Abraham Lee

@divEnd

@divClass{column-center-middle-color3}
@subheading Adding variants of font glyphs

@divClass{keep-bullets}
@itemize

@item
Adding @q{on} and @q{between} staff-line variants.

@item
Shorter and narrower variants of some glyphs for example, accidentals.
Another, more specific example could be an ancient notation breve
notehead coming in two variants one with a small or big @q{hole} within
it.

@end itemize
@divEnd

@strong{Difficulty:} easy
@strong{Requirements:} MetaFont, C++, good eye for details
@strong{Recommended knowledge:} basic LilyPond knowledge
@strong{Mentor:} Werner Lemberg

@divEnd

@divClass{column-center-middle-color3}
@subheading Grace notes

Fix problems with synchronization of grace notes.  Grace notes can
interfere with LilyPond's timing and cause odd effects, especially when
multiple staffs are used where some have grace notes and others don't.
This is one of the longest-standing and one of the more embarrassing
@uref{https://sourceforge.net/p/testlilyissues/issues/34/,bugs} in
LilyPond.

@strong{Difficulty:} medium
@strong{Requirements:} C++, MIDI
@strong{Recommended:} familiarity with LilyPond internals
@strong{Potential Mentors:} Mike Solomon (not available for GSoC 2016),
Carl Sorensen

@divEnd

@divClass{column-center-middle-color3}
@subheading Improve default beam positioning

For regular, cross-staff, broken and kneed beams.  Beaming should depend
on context and neighbor notes (see section 2.2 of
@uref{http://imslp.org/wiki/Repository_of_Music-Notation_Mistakes_%28Coulon%2C_Jean-Pierre%29,
this book}).  If possible also reduce beaming-computation time.

@strong{Difficulty:} medium
@strong{Requirements:} C++, experience with writing heuristics
@strong{Recommended knowledge:} aesthetic sense
@strong{Potential Mentors:} Mike Solomon (not available for GSoC 2016),
Carl Sorensen

@divEnd

@divClass{column-center-middle-color3}
@subheading Automated testing and documentation for openLilyLib

@uref{https://github.com/openlilylib, openLilyLib} is an extension
framework for LilyPond code providing a “snippets” repository and a
suite of integrated packages such as for example page layout tools or
scholarly annotations.  It is very powerful and promising, but to really
get off the ground two features are missing: automated testing and
documentation generation.

Automated testing is necessary to ensure modifications to functionality
don't break other functions within the library.  There is already some
Automated Testing of the “snippets” repository with Github's Travis
server, but this has to be reconsidered and extended to cover the
standalone packages too.

In order to be usable for a wider range of LilyPond users on a “consumer
level” openLilyLib needs proper documentation.  This documentation has
to be generated from the sources, so a system is needed that requires
package authors to document the input files and provide additional usage
examples, from which documentation is generated.  Ideally but not
necessarily this is implemented as a Git hook, i.e. automatically upon
each update to the repository.  We don't prescribe the tools and
approaches to be used, but the most widely used language in the LilyPond
domain is Python, so there would be some bias towards that.
Alternatively a Scheme solution could be fine so generating the
documentation would actually be triggered by “compiling” a certain
LilyPond input file.  In general it is advisable to make use of proven
concepts and tools from other languages.

The eventual output of the documentation should be a static HTML site
that can be viewed locally and/or uploaded to a website.  But it would
be beneficial if the tool would first generate an intermediate
representation (e.g. a JSON file with additional media files) from which
a Single Page Application could retrieve content for display on
openLilyLib's @uref{https://openlilylib.org, website}.  Development of
such a SPA @emph{can} be part of the GSoC project, but is optional.

@strong{Difficulty:} medium
@strong{Requirements:} Python or Scheme, static website generator(s) or
(Node.js based) dynamic web application technology. Continuous
Integration (can be learned during the bonding period)
@strong{Mentors:} Urs Liska, Matteo Ceccarello

@divEnd

@divClass{column-center-middle-color3}
@subheading Help improve compilation behavior

Automatic code analysis tools, like valgrind memory leak detection or
callgrind code profilers, provide valuable information about possible
flaws in our C++ code.  Cleaning up warnings would allow us to automate
the rejection of any patch which introduced extra warnings.

@strong{Difficulty:} medium
@strong{Requirements:} C++
@strong{Potential Mentors:} Reinhold Kainhofer (not available for GSoC
2016), Joe Neeman

@divEnd

@divClass{column-center-middle-color3}
@subheading MusicXML

Improving MusicXML import and export functions:

@divClass{keep-bullets}
@itemize

@item
Handle basic musical content export like the MIDI export (i.e. using
dedicated exporter classes, derived from the translator class).

@item
Build the XML tree of the basic musical content, add a connection from
music event to XML tag.

@item
Let all LilyPond engravers do their job.

@item
Link each output object (i.e. each stencil or group of stencils) to the
music cause (and thus to the XML tag in the XML tree).

@item
Add an XML output backend, which can then add layout information for
each output object to the XML tags.

@end itemize
@divEnd

There are several possibilities for this project, including building upon
the MusicXML export project from GSoC 2015.

@strong{Difficulty:} medium
@strong{Requirements:} MusicXML, Python, Scheme, basic LilyPond knowledge
@strong{Potential Mentors:} Reinhold Kainhofer, Mike Solomon (both not
available for GSoC 2016)

Familiarity with other scorewriters (for cross-testing) would also help.

@divEnd

@divClass{column-center-middle-color3}
@subheading Improve slurs and ties

The engraving quality of slurs and ties is often unsatisfactory. Ties
@q{broken} by clef or staff changes are not handled well.  The project
could include collecting and sorting examples of bad output, deciding on
the intended output and writing code to improve them.

@strong{Difficulty:} hard
@strong{Requirements:} C++, experience with writing heuristics
@strong{Recommended knowledge:} LilyPond knowledge, aesthetic sense
@strong{Potential Mentors:} Mike Solomon, Janek Warchoł (both not available for
GSoC 2016)

@divEnd


@node Authors
@unnumberedsec Authors

@divClass{column-left-top}
@subheading Current Development Team

@divClass{keep-bullets}
@developersCurrent
@divEnd
@divEnd

@divClass{column-right-top}
@subheading Previous Development Team

@divClass{keep-bullets}
@developersPrevious
@divEnd
@divEnd


@divClass{column-center-top}
@subheading Current Contributors

@divClass{keep-bullets}
@subsubheading Programming

@coreCurrent

@subsubheading Font

@fontCurrent

@subsubheading Documentation

@docCurrent

@subsubheading Bug squad

@bugsquadCurrent

@subsubheading Support

@supportCurrent

@subsubheading Translation

@translationsCurrent

@divEnd
@divEnd


@divClass{column-center-bottom}
@subheading Previous Contributors

@divClass{keep-bullets}
@subsubheading Programming

@corePrevious

@subsubheading Font

@fontPrevious

@subsubheading Documentation

@docPrevious

@c    uncomment when we have any previous members -gp
@c @subsubheading Bug squad

@c @bugsquadCurrent

@subsubheading Support

@supportPrevious

@subsubheading Translation

@translationsPrevious

@divEnd
@divEnd

@node Acknowledgements
@unnumberedsec Acknowledgements

@divClass{column-center-top}
@subheading Acknowledgements

@divClass{keep-bullets}
@acknowledgementsCurrent
@divEnd
@divEnd


@node Publications
@unnumberedsec Publications

@divClass{column-center-top}
@subheading What we wrote about LilyPond

@divClass{keep-bullets}

@include we-wrote.itexi

@divEnd
@divEnd

@divClass{column-center-bottom}
@subheading What people did with LilyPond

@divClass{keep-bullets}

@include others-did.itexi

@divEnd
@divEnd

@contactUsAbout{academic papers}


@node News
@unnumberedsec News

@divClass{heading-center}
@warning{Many old announcements and changelogs can be found in
the @ref{Attic}}
@divEnd

@include web/news-front.itexi

@include web/news.itexi


@node Attic
@unnumberedsec Attic

@divClass{column-center-top}
@subheading Announcements

Announcements and news by version:
@uref{http://lilypond.org/doc/v2.16/Documentation/web/index#Lilypond-2_002e16_002e0-released_0021-August-24_002c-2012-1,v2.16},
@uref{http://lilypond.org/doc/v2.14/Documentation/web/index#LilyPond-2_002e14_002e0-released_0021-June-6_002c-2011,v2.14},
@miscLink{announce-v2.12,v2.12},
@miscLink{announce-v2.10,v2.10},
@miscLink{announce-v2.8,v2.8},
@miscLink{announce-v2.6,v2.6},
@miscLink{announce-v2.4,v2.4},
@miscLink{announce-v2.2,v2.2},
@miscLink{announce-v2.0,v2.0},
@miscLink{ANNOUNCE-1.2,v1.2},
@miscLink{ANNOUNCE-1.0,v1.0},
@miscLink{ANNOUNCE-0.1,v0.1}

Descriptive list of changes by version:
@uref{http://lilypond.org/doc/v2.16/Documentation/changes/index.html,v2.16},
@uref{http://lilypond.org/doc/v2.14/Documentation/changes/index.html,v2.14},
@uref{http://lilypond.org/doc/v2.12/Documentation/topdocs/NEWS,v2.12},
@uref{http://lilypond.org/doc/v2.10/Documentation/topdocs/NEWS,v2.10},
@uref{http://lilypond.org/doc/v2.8/Documentation/topdocs/NEWS,v2.8},
@uref{http://lilypond.org/doc/v2.6/Documentation/topdocs/NEWS,v2.6},
@uref{http://lilypond.org/doc/v2.4/Documentation/topdocs/out-www/NEWS,v2.4},
@uref{http://lilypond.org/doc/v2.2/Documentation/topdocs/out-www/NEWS,v2.2},
@uref{http://lilypond.org/doc/v2.0/Documentation/topdocs/out-www/NEWS,v2.0},
@uref{http://lilypond.org/doc/v1.8/Documentation/topdocs/out-www/NEWS,v1.8},
@uref{http://lilypond.org/doc/v1.6/Documentation/out-www/NEWS,v1.6},
@miscLink{NEWS-1.4,v1.4},
@miscLink{NEWS-1.2,v1.2}

@divEnd

@divClass{column-center-bottom}
@subheading Thanks

Thanks to developers, contributors, bug hunters and suggestions for
@miscLink{THANKS-2.16,v2.16},
@miscLink{THANKS-2.14,v2.14},
@miscLink{THANKS-2.12,v2.12},
@miscLink{THANKS-2.10,v2.10},
@miscLink{THANKS-2.8,v2.8},
@miscLink{THANKS-2.6,v2.6},
@miscLink{THANKS-2.4,v2.4},
@miscLink{THANKS-2.2,v2.2},
@miscLink{THANKS-2.0,v2.0},
@miscLink{THANKS-1.8,v1.8}

@divEnd

@divClass{column-center-bottom}
@subheading Changelogs

Developers' changelogs by version:
@miscLink{ChangeLog-2.10,v2.10},
@miscLink{ChangeLog-2.3,v2.3},
@miscLink{ChangeLog-2.1,v2.1},
@miscLink{ChangeLog-1.5,v1.5 (1)},
@miscLink{CHANGES-1.5,v1.5 (2)},
@miscLink{CHANGES-1.4,v1.4},
@miscLink{CHANGES-1.3,v1.3},
@miscLink{CHANGES-1.2,v1.2},
@miscLink{CHANGES-1.1,v1.1},
@miscLink{CHANGES-1.0,v1.0},
@miscLink{CHANGES-0.1,v0.1},
@miscLink{CHANGES-0.0,v0.0}

@divEnd