mcl is a MUD client running in a Virtual Console under Linux or using standard TTY routines under any other UNIX. Embedded Perl or Python offer very high tweakability. Other features include huge scrollback, a stable input line with the MUD prompt, Perl regexps for actions and substitutions.
SmartHTML is yet another HTML preprocessor. It allows you to write Web pages in a language more sane than HTML: paragraphs are automatically inserted when two consecutive newlines are encountered. Special symbols like < & etc. are automatically replaced. Tags look like texinfo: @tagname { contents }. Written in Perl, it allows tags to run Perl subroutines on the contents, allowing e.g. automatic generation of a table of contents, smarter generation of links, macros which can define HTML code which has to be maintained in only one place, etc.