I added a hook to Xtreams files this evening. The hook by now is in FileDirectory (no comment... I'll be happy when a replacement is integrated in Squeak/Pharo). ((FileDirectory default / 'toto.txt') writing encoding: #ascii) write: 'hello world'; close. ((FileDirectory default / 'toto.txt') reading encoding: #ascii) rest. I didn't hook into StandardFileStream, but rather a simplified version of David Lewis IOHandle. I separated this stuff in Xtreams-SqueakExternals. Anyway, this is not really related to Xtreams, most of the functionality should be in core (apart reading/writing/appending which might better return in Xtreams-Terminals). I also slighlty modified XTFileReadStream and XTFileWriteStream to fit some Squeak specific API. Maybe I could have just used the VW API and provide compatibility layer... We'll see later. Nicolas