Fixed bugs:

• SRFI-42 implementation was out dated. #36
• letrec*evaluated init values incorrect order. #38
• char-set-map raised an error when passing empty map. #39
• thread-sleep! stopped in millisecond instead of second. #40
• thread-sleep! only accepted exact integer. #41
• Thread related procedures timeout value didn't accept time object. #42
• string-split caused SEGV when empty match was given. #43
• digit-value returned truncated value for half valued numbers. #44
• Predefined charset name of regular expression resolved incorrectly.
• interaction-enviromnent in (scheme repl) was defined as a variable instead of a procedure.

Improvements:

• Compiler eliminates no side effect expression more eagerly.
• Improved compiled code of filter, remp, remove, remv and remq.
• hashtable-update! searches only once.
• regex-group can accept named match.
• Improved performance of vector-map, vector-for-each and string-for-each.
• Unicode 7.0.0 has been supported.
• regex-replace has been added.
• Regular expression replace procedure can understand $p and $P as pre-match and post-match placeholder.

New features:

• Heap data structure library (util heap) has been added.
• SRE conversion library (text sre) has been added.
• SRFI-115 has been supported.

Incompatible change:

• sash is now a symbolic link, the binary name is sagittarius. #37
• Handling empty match of regular expression has been changed to Perl compatible.
• Character sets are not only ASCII but Unicode.