Firefox
Firefox and Thunderbird are backported rpm's from Scientific Linux 4. These backports currently do not take too much extra effort, mainly just time. But The Upstream Vendor has said that when Firefox 3 comes out, they will update the Firefox to 3. The time and effort to backport this version of firefox and thunderbird to SL 309 is more than we have to offer.
Seamonkey (the new name for mozilla) is still available on SL 309

pcp
PCP doesn't seem to be used much, and we were concerned about the amount of time that would be needed to fix it if there was a critical security update needed.

Thunderbird
Firefox and Thunderbird are backported rpm's from Scientific Linux 4. These backports currently do not take too much extra effort, mainly just time. But The Upstream Vendor has said that when Firefox 3 comes out, they will update the Firefox to 3. The time and effort to backport this version of firefox and thunderbird to SL 309 is more than we have to offer.
Seamonkey (the new name for mozilla) is still available on SL 309

yumi
Yumi hasn't been supported much since we put it in, that is why we have yumex in SL 4 and 5. We were concerned what would happen if there was a critical security update needed.