command line unix tool suite that attempts to be posix compliant where sane
http://landley.net/toybox/
Posix compliant glibc replacement
http://www.musl-libc.org/
Standards compliant C compiler
http://pcc.ludd.ltu.se/
Fast lexical scanner ( a lex is required by pcc)
http://flex.sourceforge.net/
Berkley yacc (a yacc is required by pcc)
http://invisible-island.net/byacc/
BSD ported M4 with linux dependent functions added (required by flex)
http://haddonthethird.net/m4/
Because its still the best for processing the common Makefile
http://ftp.gnu.org/gnu/make/
Packages currently in the base system to be replaced at earliest convenience: