Hi There,
We didn't drop support to any browser with the latest release so you can expect it working on any browser it was working before.
Some support was improved (see the changelog here:
http://www.lightstreamer.com/distros/Lightstreamer_Allegro-Presto-Vivace_5_1_1_Colosseo_20131220/Lightstreamer/CHANGELOG.HTML#web_clientand if you're not on the latest 5.0.1 version here:
http://www.lightstreamer.com/distros/Lightstreamer_Allegro-Presto-Vivace_4_1_1_Duomo_20130110/Lightstreamer/CHANGELOG.HTML#web_client )
The library is compatible with all the major browsers (down to IE6) and probably with any minor browser too. It runs on both desktop and mobile browsers. (it can also run on node.js)
A few details on the different level of support can be found here:
http://goo.gl/kwREX
(the matrix currently fails to mention IE11, it goes without saying we're compatible with that too)