thank you very much for the new project managment system in V. 4.40.
But I think this first approach is a bit confusing, because you can edit a project (and its files) and stand-alone sourcecode at the same time.
There is no strict seperation between this files and the files of a project. And there is still a bug in the function 'close project' -> not all project-related sourcefiles will be closed, only the first one)
[see my post in the german forum: http://www.purebasic.fr/german/viewtopi ... 373#253373]
My suggestion is to strictly seperate the projects (and their source files) from 'unprojected' sourcefiles.
To get a straight project-overview you can use the toolpanel for example (in german "Werkzeugtafel") to display and manage the projects.
You can and list them in a treeview gadget for example, like in the following fake-screenshot I made.

Each time, you click on a project entry, the related sources will be loaded into the editor tabs on the right side. So you can easily switch between your projects and their files without confusing.
The first entry in the project list is reseverd for single sourcecode which are not part of any project (this quasi would be the mode, PureBasic managed/displayed the sourcecodes before 4.40).
The dark side of this suggestion for you could be: to write the management system completely new from scratch. :roll: