Ganz MAVAG was broken up in 1988 already - into somewhere around a dozen subcompanies. The railway department went through a couple owners relatively unsuccessfully and at some point after 2001 vanished with Connex/Veolia as the last owner; the engineering group (and know-how) ended up with Molinari Rail, a Swiss consulting company for railway engineering. Supposedly at some point just before 1998 there was a chance for it to merge into Adtranz (which would have likely kept Ganz alive as a wholesale railway manufacturer), but that died off when Bombardier bought up Adtranz from Siemens.
The factory in Budapest is currently organized as part of the Ganz Holding (Ganz Motor Ltd), and produces diesel engines and bogies as well as - supposedly - passenger waggons. Skoda seems to also have bought up part of it and manufactures trolley busses and trams there (Ganz-Skoda Electric Ltd), though on a hunch i'd say that's for the geo-return to have one up on the competition in Hungarian contracts.