OpenLiteSpeed is the Open Source edition of LiteSpeed Web Server Enterprise. OpenLiteSpeed contains all of the essential features found in LiteSpeed Enterprise, including LSCache (plugin needed for WordPress).
To install OpenLiteSpeed (DA 1.57 or higher is needed, it would run fine with pre-release binaries too):
1) You must have CustomBuild 2.0. If you do not, upgrade to CustomBuild 2.0
2) You can either run this in step 2 of the CB2 install guide, or do it after. Run the following to set the options.conf to use OpenLiteSpeed and lsphp:
./build set webserver openlitespeed
./build set mod_ruid2 no
./build set php1_mode lsphp
./build php n
If you have more than 1 php version, set php2_mode lsphp for all other php#_modes.