JEdit is simply the best Java-based editor. Siegfried contributed the Mac OS X native launchers

Canoo WebTest

Canoo WebTest is functional web testing tool based on ANT. Siegfried wrote a M1 and M2 plugin some years ago.

Java Mail Server

Java Mail Server is a small stand-alone SMTP/POP3 server written by Eric Daugherty well suited for a development and testing mail server running on all platforms. Unfortunately it is under GPL and not Apache license which makes integration into existing applications impossible. Siegfried is quoted as long-standing contributor which is a very polite written statement for altogether two patches - thanks Eric