How do you do team development today in C# or other languages?  Each organization does it a little different.

If you are using TFS for source control you can still use TFS with Pega Robotics.  To do so, you will need to use the Visual Studio plugin, since Pega Robotics Studio standalone does not support TFS.  

If you use SVN and perhaps TortoiseSVN for your client, you can use either the Visual Studio plugin or the Pega Robotics Studio since you will be performing source control at the file system level.

It is important is to implement file locking.  Merging at the file level is not recommended.  Each file contains positional information that may be different for each user.  This makes a automatic merge difficult and a manual merge very tedious.  Additionally, IDs are generated for controls/variables/automations/etc. when they are created.  The IDs are used to identify objects throughout the project, instead of their names.  It is therefore important to lock certain files when adding automations/editing adapters/adding variables and then informing the team to update those files when the update is checked in.

1) If you are using  open span , it support TFS for code management , each one can check-in their code in TFS, or any other repository just like in .C# , ASP.net or JAVA code.

2) With this you can share your code and do the development locally also, but I will recommend to keep your file lock while coding so as to avoid merge at later stages.