ViennaSQL is a GUI SQL client written in 100% Java. ViennaSQL can communicate with any database that has a JDBC driver. It should run anywhere Java runs. [edit]
A few years ago, open source advocates were pleased that the city of Vienna was planning a migration from Windows to Linux for municapally-owned computers. But a recent report from Austrian news service ORF.at (Google translation here) shows that the migration hasn't been without problems: 720 computers in kindergartens are to be converted back from Linux to Windows Vista at the cost of 105,000 euros. While someone in Microsoft sales is probably happy about this, it may not be the Linux black eye that it at first appears to be.