The main difference is that it is one single file RegexPlugin.fmx now and no need for an additional *.dll file. This improvement is possible due to the new LisWorks version 5.1 published yesterday and Edi Weitz' work to adjust FM-Plugin-Tools.
The features of the plugin are unchanged.
Another effect of the new LW version will be that it is possible to build plugins for MacOS X now and we will soon have Regex-Plugin for Mac too.
See http://jensteich.de/regex-plugin/index.html
Jens