The information was made public in the CDR database
Team Fortress Classic, a game developed by Valve as a mod for Half-Life, will arrive on Steam for Linux, soon.Team Fortress Classic, also known as TFC, started its life as a mod for Half-Life, but it was released as a standalone a few years later.
According to Valve, Team Fortress Classic features over nine character classes – from Medic to Spy – enlisted in a unique style of online team warfare.
The information about the Linux version is taken from the CDR database and by no means is it completely certain. The CDR Database is a record of data that describes every Steam game and subscription provided by Valve for the Steam service.
Usually, the new entries in the Steam database are first visible in the CDR Database before their official launch.