Code Editor with Switchable Session Tabs?

I'm using Notepad++ and I really like it, though one problem I have with this is, I'm always working on multiple projects and when I have the documents of one project spread across in Notepad++, which can be up to 15 documents, then I sometimes open up documents from other projects, which can be 2, 3 or more documents just to do slight modifications, and then when I come back at a later point I've then totally lost my overview and don't even know anymore which document belongs to which project. To even add to it, I also open up documents from third party projects just to learn from them - it happens that multiple documents have the same names (e.g. header, footer, sidebar), which makes it hard to differentiate them.

So my question would be is there a code editor with "session tabs", which is how I call it, where I simply can switch back and forth between different type of sessions.

For example:
1. My Project 1
- documents 1, 2, 3, 4, 5 etc.

2. My Project 2
- document 1, 2, 3, etc.

3. Third Party Documents
- document 1, 2, 3, 4, 5, 6 etc.

It would be best if I could switch between them on the fly, without having to save and load them.

Notepad++ allows the saving and loading of session files, but I find it in the way how it's implemented into Notepad++ very impracticable.

I tried Eclipse but I couldn't see any way of storing selected documents in separated tabs.


I'd appreciate any suggestions with which software I can achieve this.