XIDE is organized in projects like VO. But the “Empty project” that XIDE shows at the first start can be used only for standalone prg files, but not for applications. As said, XIDE has projects, and every project can contain from zero to many applications. Contrarily to VO, projects can contain not only applications, but also application groups to better organize the applications in the project. XIDE knows two different export files:

• .viaef files contain a single application, i.e. a single executable or library. These files can be imported in any existing project (but not in the empty project!)
• .vipef files contain an entire project, i.e. all the applications that are contained in a project

A explanation by the author can be found here: https://www.xsharp.info/forum/public-chit-chat/590-net-simple-database-what-to-use?start=40