You can use VNC server on rarspberryPi and VNC clients on developers laptops. You can use tightvncserver package for this. In most typical setup, each client connecting to VNC will see exatcly the same screen, will control the same mouse pointer etc. I believe you would like to setup it so that every one that logs in gets his own individual screen.
To start VNC session, you can type:
where X is a slot number. You can use :1, :2, :3, etc. It will ask your for password twice. It's the password clients will use to authenticate to the VNC server.
You can run multiple servers as long as each of them have different slot number. You have to specify proper slot number in VNC client when connecting, using proper port number. Port 5901 is slot :1, 5902 is slot :2 etc.
If they don't need graphical output, you could setup SSH server and create accounts for each developer. Developers with Linux systems or develpers who knows how to setup X server on their machines could also use SSH X forwarding feature to run some graphical programs.
Note that you won't be able to use such a setup for many developers at the same time as RaspberryPi is just not powerful enough. Each such session will have it's own programs running and there is really not much RAM and CPU power available.