We are a group of developers from around the globe who have helped to develop the Half-Life 2 Capture the Flag game modification since the first beta release in February 2005.
Here is the official mapping tools for HL2:CTF 2.1
This is the most up-to date version of the Half-Life 2 CTF sdk.
This is a developer FGD for Half-Life 2 CTF released by the original developers in 2005
Half-Life 2: Capture the Flag 2.1 Full Windows Installer.
Half-Life 2: Capture the Flag 2.1 full zip archive that can be installed by both clients and server administrators.