Eclipse was filtering the list of installable add-ons
After I installed Linux Mint 10 to get away from Unity bugs, I went to reinstall Eclipse.
First from Synaptic, but the version was a bit old. I did not manage to install Maven.
Next a download and manual install of Helios. Filtering the list of available add-ons seems to launch an enormous job. Type one letter and wait 2 minutes.
Hope I can get it all running before lunch. :-{
