I like Markdown because it allows text files to look normal, and then makes nice HTML out of them. Discount is a fast Markdown translator written in C. Unfortunately, it won't compile on my debian development machine:
cc -L. -o markdown main.o -lmarkdown ./libmarkdown.a(markdown.o): In function `listblock': markdown.c:(.text+0x1166): undefined reference to `isdefinition' collect2: ld returned 1 exit status make: *** [markdown] Error 1
Hmmm. Aha - I was using an outdated version, the latest version (1.3.1 as of Feb 2009) compiles fine.