Which Version Control Systems support LDAP/AD users and groups

VisualSVN Server allows you to manage svn repository permissions using AD users and groups. And the standard edition is free and meets most organization's needs.

Not to be flippant, but really, just about all of them do. Since PAM on Linux supports LDAP, standard unix accounts (and therefore, standard files) support LDAP, almost all Linux-compatible version control systems should work fine. Likewise, Windows supports LDAP through Active Directory (AD is basically LDAP with kerberos and some deployment tools, as I understand it), and so any version control that works with standard windows accounts should support it too. I'm pretty sure this all applies to OS X as well.

Git certainly does - you need to set up PAM to use pam_winbind.so and pam_mkhomedir.so. Create a group (either locally or in AD, depending on how you want to do it) and create your git repositories on the origin server with the --shared flag. This will tell git that you are sharing the repository amongst multiple users, and it will set up permissions appropriately.