Dia2Code and AutoDia
I mentioned at tool that converts Dia diagrams to SQL last month, tedia2sql, and I'm not sure why I neglected to also mention Dia2Code and AutoDia also.
Dia2Code will convert a Dia diagram to any of a variety of languages including C, C++, Java, PHP, Python, Shapefile, SQL, and hopefully C# as soon as version 0.9 becomes available. It's available from here:
AutoDia will convert code in a variety of languages to either a Dia diagram or Graphwiz (for generation of other image files such as png), dot, vcg, xvcg (for Postscript), or HTML etc. if you write your own template (which supposedly only takes 20 minutes). AutoDia will handle source files in several languages including Perl, Python, PHP, C++, Java, Torque, DBI, and SQL. It's available from here: