Browser maker and version on T610?

Who makes the browser on the SonyEricsson T610 (a T-Mobile branded one
should that make any difference).

I believe SE touts the T610's browser as being WAP 2.0 compatible, and with
support for xHTML (in addition to the standard WML). Does anyone know of a
good source of information on the specific capabilities of xHTML? How about
in relation to the browser maker and version on the T610 (not sure which
firmware this phone has).

Google has turned up some good reading, but not answers to these specific
questions.

Also, REQWireless lists their WebViewer MIDP browser (HTML only) as
compatible with the T610, right on their website. I have had some success,
but generally it is very unstable on the T610. The WebViewer Lite, which
they apparently ported just for the Nokia 6310i (non-graphics), works
somewhat decent on the T610 as well, without graphics of course. However,
sometimes it crashes as well and sometimes it works decently.

Is there a good HTML browser written for J2ME/MIDP alternative to WebViewer
or WebViewer Lite?

Thanks for any info.