I have several development machines where I am the administrator. We are using AD in my organization but is maintained by and offshore IT group any request takes a long time.

We are currently granting access to developers on development machines manually so it's a bit annoying to maintain although at least it's fast. We have also a lot of external consultants that need to use those machines for some time.

Is there any tool or method to maintain a set of users synced on those machines without the need add them to an AD group?