Issue 3732: Web: Rewrite "Features" content

The "Features" page had some problematic content and structure.
This commit makes some points more clear, removes problematic
claims and introduces some more points pro LilyPond.

Additionally replace some "color2" divs by generic divClass

diff --git a/Documentation/web/introduction.itexi b/Documentation/web/introduction.itexi
index 8fd6aaa73999cf33b4893e1a086bcff1f4e9633a..5d2f8c629d039c7d04a02404a8c0773d89fb65fc 100644 (file)
--- a/Documentation/web/introduction.itexi
+++ b/Documentation/web/introduction.itexi
@@ -116,30 +116,49 @@ best-engraved classical scores.  This is further explained in our
 
 @divEnd
 
-@divClass{color2}
+@divClass{column-center-top}
 @subheading Text input
 
-@imageFloat{lilypond-book,png,right}
-
 @subsubheading Everything is explicit
 
-LilyPond takes ASCII input, which you can produce in your favorite
-text editor, quickly and comfortably.  The input contains all the
-information, so there is no need to remember complex command sequences:
-simply save a file for later reference.
+LilyPond processes text input, which contains all information
+about the @emph{content} of your score and can easily be read
+by any human or another program. There are no obscure
+settings hidden behind menu items and binary file storage.
+
+Read more about this concept on @ref{Text input}.
+
 
 @subsubheading Tweaks are robust and traceable
 
-@subsubheading Text files are robust
+If you have to change anything in the layout this tweak will
+also be explicitly visible in the input file in human-readable
+form, so you will always be able to retrace what you've done.
+If you should accidentally break anything you can easily revert
+or modify any decision without being at the mercy of an
+@emph{Undo} function.
+
+
+@subsubheading Text files are failure- and future-proof
+
+Text files are very robust against file corruption. And as they are
+human-readable, you will always be able to interpret them even if
+you don't have access to the programs that created them.
+
 
 @subsubheading Manage your scores with version control
 
+Text files are applicable to be managed by version control. Go
+for it and experience infinite and selective undo/redo mechanisms
+and the full development history of your scores. Version control
+may also open up new (collaborative) workflows for you.
+
 @divEnd
 
-@divClass{color2}
+@divClass{column-center-top}
 @subheading Usability
 
-@imageFloat{frescobaldi-lilypond-editor-small,png,right}
+@imageFloat{lilypond-book,png,right}
 
 
 @subsubheading Effective layout choices
@@ -154,8 +173,8 @@ and slurs and beams are sloped, automatically!
 @subsubheading Mix music and text
 
 Put fragments of music into texts without cutting and pasting
-pictures.  Integrate music into @LaTeX{} and HTML seamlessly, or add
-music to OpenOffice.org or LibreOffice with OOoLilyPond.  Plugins are
+pictures.  Integrate music into @LaTeX{} or HTML seamlessly, or add
+music to OpenOffice.org/LibreOffice with OOoLilyPond.  Plugins are
 also available to allow LilyPond code in various blogs and wikis, making
 online collaboration possible.
 
@@ -169,45 +188,74 @@ speech-recognition software to edit LilyPond files.  Even users
 who are totally blind can use screen-reading software to write
 LilyPond files -- an impossible task in graphical-based
 score-writing programs.
+You can see a spectacular score on @ref{Examples}.
 
-@subsubheading Enhanced editors
+@subsubheading Editor diversity
 
-Several developers, themselves active LilyPond users, have also
-written tools specifically aimed at making the process of editing
-LilyPond files faster and more effective.  For some examples, see
-@ref{Easier editing}.
+Several developers, themselves active LilyPond users,
+have written tools specifically aimed at making the process of editing
+LilyPond files faster and more effective; you are not tied to
+a single user interface but can use different tools for different tasks.
+You can even use a full-fledged LilyPond editor at home and use your
+mobile phone's notepad app to edit the files on the go. For some examples,
+see @ref{Easier editing}.
+@c TODO: Change this when the new pages have been written and pushed
 
 
 @divEnd
 
-@divClass{color2}
+@divClass{column-center-top}
 
 @subheading Extensible design
 
 @subsubheading Easy management of style sheets
 
+All layout settings can be changed to suit your personal typographical
+taste. So you can easily write style sheets that change every aspect of
+LilyPond scores' default appearance. As these are also written as text
+and can be stored in separate files you can simply switch between two
+stylesheets to produce scores with a completely different appearance or
+layout.
+You want to print a score on A4 paper and project it with a beamer,
+one system per page? LilyPond's layout engine will effortlessly produce
+both from the same input.
+
 @subsubheading Add your own functions
 
-All settings can be changed to suit your personal typographical
-taste.  If that still is not enough, there is always the built-in
-scripting language Scheme, a dialect of the powerful language
-LISP.  Settings, variables and functions are all documented in the
+If that still is not enough, there is always the built-in
+scripting language Scheme, which can access LilyPond's layout
+engine at the same level as LilyPond itself does, making it
+a @emph{very} powerful tool.
+Settings, variables and functions are all documented in the
 comprehensive program reference manual.
 
+@subsubheading Process scores programmatically
 
-@subsubheading Create new frontends for LilyPond
+LilyPond input files can fully be edited or even generated by programs
+and scripts. This can for example be used for algorithmical composition.
+But you can also access the musical content for analysis, or manage
+input fragments in a database. There are no limitations except your
+imagination.
 
-E.g. web applications
 
-(Link to productions or similar page).
+@subsubheading Create new tools using LilyPond
+
+As LilyPond isn't a monolithic GUI program but a command line tool it
+can be used from within other applications too. This way it is possible
+to equip tools like e.g. web applications with LilyPond's engraving
+power. There already exist several online tools using LilyPond.
+
+@c (TBD: Add a link to the new @ref{Applications} page.
 
 
 @divEnd
 
-@divClass{color3}
+@divClass{column-center-top}
 
 @subheading Environment
 
+@imageFloat{frescobaldi-lilypond-editor-small,png,right}
+
 
 
 @subsubheading Excellent support
@@ -215,8 +263,12 @@ E.g. web applications
 LilyPond runs on all popular platforms: GNU/Linux, MacOS X, and
 Windows.  LilyPond comes with extensive documentation and hundreds
 of example files.  There is an active user community answering
-questions on the lilypond-user mailing list, while the development
-team makes sure that problems are solved quickly.
+questions on the lilypond-user mailing list, offering you friendly
+help. The response time is usually very short, and often brillant
+solutions to reported problems are developed. Thanks to the close
+interaction with the development team such solutions are regularly
+included in LilyPond itself.
+Read more in @ref{Community}.
 
 
 @subsubheading Free software
@@ -228,6 +280,7 @@ It's also free (as in @qq{speech}) software.  It comes with source
 code, and permission to change and copy it.  So, are you irritated
 by a bug, or yearning for a feature? Simply add it yourself, or
 pay someone else to do it.
+Read more on @ref{Freedom}.
 
 @divEnd
 @divClass{column-center-bottom}