A little while ago, DarkMatter and his team released version 0.7.0 of DatGen. This editor, originally made for SimCity 4, edits Package files used in the Sims 2 and SimCity 4. Although the program is currently not yet complete, and still far from very user friendly, it is in active development. In the future there will be plug-ins which will make a lot of tasks like editing your Sims very easy to do. The program has seen version 0.7.3 by now too, which you can get from the downloads page on the site. If you ever feel like talking to the people behind it, then you can find the DatGen chatroom at The Sims Resource chat.