5 - default extension, search path.
10 - inputfile name in output.
12 - Split Input_* parsing steps to enable marking
20 - | checks for bar in a voice (Barcheck_req)
22 - naming (Hungarian notation, svec vs. Array)
23 - cleanup PScore, Score
24 - removed Staff_commands, plugging commands into Staff_column directly
27 - huge memleak fixed; unearthed lots of bugs
34 - Move breaking stuff into a separate class Break_algorithm
35 - dependencies for Staff_elem's
38 - updated doco to .pod
39 - include files from .ly
41 - Rational for time measurement
42 - directionalspanner/textspanner
45 - grouping code: LilyPond can set advanced multibeams.
51 - robust Staff_commands
54 - robust Input_commands
55 - merged Vertical_/Horizontal music
56 - PARTIALs with duration
57 - modularized lexer: multiple runs
60 - notenames configurable
72 - Horizontal/Vertical music