You probably should be reading the Pacemaker site clusterlabs.org
This site conserves Heartbeat specific stuff. See Site news for details.
The driving forces, developers and Linux vendors, as well as the Open Source High Availability Clustering community in general, have moved to the HA stack based on Corosync 2.x + Pacemaker.
To reduce fragmentation of the community, we agreed to consolidate everything Open Source HA Cluster and -Framework related on Clusterlabs, the Pacemaker site.
This Linux-HA web site mostly conserves information specific to the Heartbeat cluster stack, either used stand-alone (in "haresources" mode), or together with the Pacemaker cluster resource manager.
Even longer ago, it used to be MoinMoin wiki based. This original site continues to exist at the original location, to preserve direct links that people may have posted in their blogs, mentioned in archived mailing list posts, or have been put on other projects' web sites. However, please be warned that much of the information recorded there is now obsolete, outdated, or hard to follow.
To prevent wiki-spam, automatic account creation is not enabled on this wiki. Today, this wiki is mostly static, and conserves information specific to the Heartbeat (+ Pacemaker) based cluster stack. The focus of Linux HA Clusters has shifted to Corosync + Pacemaker for some time now.
If you would like to contribute to Linux HA Clustering (and you would greatly help us out if you did!), check out the Clusterlabs Wiki instead, drop us a note on irc://irc.freenode.org#clusterlabs, or send an email to email@example.com.