A new approach is proposed to transparently share familiar single-user editors without modifying their source code. This approach tweaks a classic diff algorithm to derive edit scripts between document states. Concurrent edit scripts are merged to synchronize states of coauthoring sites. Our concept-proving prototype currently works with familiar, heterogeneous text editors such as GVim and WinEdt that can be adapted to support two basic interfaces, GetState and SetState. The adaption is less expensive and more robust than recent approaches such as ICT and CoWord, which must understand and translate editing operations at the operating system level. Experimental data show that our approach is able to provide sufficient performance for near-realtime group editing.