microStudio supports concurrent access with multiple editors
I have a multiplayer game, and when debugging it I have two tabs open to the same project in order to run two clients. I have found that access locking is implemented on the source files. While I am in the process of editing a source in one tab, during the period where I made changes but they have not been updated with the server ( before the green check mark appears ), that the other tab has a message indicating a lock on the source. Once the update from first tab is complete, the second tab gets updated for those changes and the lock is removed.
This I figure applies to shared projects ( multiple users in one project ), so that working on the same sources at the same time is possible.