A new documentation is available for Squash TM 2.0 and later versions, check it here
How to install and configure a plug-in in Squash TM from 1.13 release and onwards:
1. Download the plug-in
2. Stop Squash TM
3. Copy the unzipped file in:
C:\<rep>\squash-tm\plugins\ for Windows
/usr/share/squash-tm/plugins/ for Debian/Ubuntu
/usr/lib/squash-tm/plugins/ for Redhat/CentOS
/opt/squash-tm/plugins\ for tarball
5. Relaunch
Rem : <rep> = Squash install repertory
How to install and configure a plug-in in Squash TM 1.12 and under:
1. Download the plug-in
2. Stop the software
3a. If it is only a jar, put the jar in ~squash/bundles.
3b. If it is an archive (zip or tar.gz) then unpack it, you should have 3 directories inside : /bundles, /config and /plug-ins. Copy the bundles files into ~squash/bundles, configure files in ~squash/config and plug-ins files in ~squash/plug-ins.
4. Remove the felix cache directory, ~squash/felix-cache
5. Start the software
Rem : ~squash = Squash install repertory