The PSP (Primary Server Program) portion of Valve's TeamFortress Classic release is available on this page from GameCenter. The 75 MB download is available after filling out a form for high-bandwidth users who plan on running servers. This is so servers can already be in place and online tomorrow, when the plan is to release the customer client for download bright and early at 9:00 AM Pacific time. The client download will be a still healthy 19 MB or so. In the announcement of all this, Valve also mentions the Linux Half-Life server is in the final stage of development and will go into testing later this week.