The App-V OSD Editor is a GUI tool that allows you to open an existing App-V OSD file and edit it. All the possible categories are read from the App-V OSD file and displayed in the appropriate tab. You can insert and/or delete values from the OSD as you like. So you don't have to worry and opening and closing tags or anything like that any more. There are however some fields you can not edit with the OSD Editor. This is by design: these are fields that should never be edited like for example the GUID of the sequence. Additionally, the App-V OSD Editor also educates you on the meaning of some of the XML tags that can be used in App-V OSD files.