We said we were going to attempt monthly updates from here to the end, and we have 'near enough' done it this time, give or take a week. In our mad rush to get Beta 4 out the door we only have a 'patch' version available at the moment (i.e. you will need a working copy of Beta 3 installed before upgrading). A full installer will be available sometime later today. Enough talking, onto the mirrors and lets get gaming.
NOTE: You will need Beta 3 installed BEFORE you use this to patch to Beta 4
Be sure to read the Player Guide if you aren't sure what Hidden : Source is all about!
We appreciate we've not given any time for servers to be prepared - sorry about that, we got a bit over eager and kind of forgot to do it earlier!
A changelog is available for those that wish to know what's changed between B3 and B4, the list is not massive, but it's not without substance.