Porting machine Ryan 'Icculus' Gordon shared a screenshot on twitter of the work he has put into the open source release of Serious Engine 1 working on Linux & Mac.
After resolving some code conflicts, it's also now working on Linux:
Be fun to see it all properly merged and released, so we can enjoy some classic Serious Sam on an open source engine.
You can also see a bit of Linux porting history, as Ryan put up the original changelog when he first ported it to Linux. Find more on that here.
You can find the official github here.