There is great news for those of us who have to log into Office Communications Server (formerly Live Communications Server) at work — the SIPE project has resumed and has released a very functional version (now at 1.5).

SIPE is a plug-in for Pidgin, allowing it to log in and exchange messages on an LCS server (Communicator server).

https://sourceforge.net/projects/sipe/

Installing SIPE is more of an “advanced user” operation as it currently must be compiled. Lucky Ubuntu 9.04 (Jaunty) users can install SIPE simply by running “sudo apt-get install pidgin-sipe) at the command line. I believe packages for Red Hat/Fedora/CentOS are not yet available in their yum repositories.

Visit the SIPE project page and forums (https://sourceforge.net/forum/forum.php?forum_id=688534) for more information as well as installation instructions.

Basically, the install procedure is like this:

sudo apt-get install pkg-config libglib2.0-dev libgtk2.0-dev pidgin-dev libpurple-dev libtool intltool comerr-dev

Then do the following:
tar -xjvf pidgin-sipe-*.tar.bz2
cd pidgin-sipe-*
./configure –prefix=/usr
make

sudo make install or run make install as root.

I’m quite sure you also need the build-essential meta package to compile the code if using Ubuntu or similar.

If you have any questions or need any more information, post to the SIPE forum (after reading all the readmes and information already provided of course. ). http://sipe.sourceforge.net/install/ has more installation instructions, including those using the developer’s unofficial Ubuntu repository and installing from the latest git commits.