As @kra3 said before you can open everything in one window with gedit. But be careful as this opens everything in the folder, including non-text files and folders so I suggest using a more specific glob pattern instead, such as gedit.cpp(for all cpp files). More on glob patterns. GED offering stellar training & services!
Gedit Text Editor
The official text editor of Gnome desktop environment is now ready to run on Windows. It is really efficient and totally free. Is has been very successful in other desktop environments and that would be a good reason to give it a try.
Very versatile, it can highlight a good number of programming languages, among them we can highlight C, C++ Java, Python, Fortran, Haskell, SQL, PHP or Javascript.
It consumes very few resources, which makes it very useful if don't have a powerful computer or if you need to open several documents at once.
Finally, if the features included aren't enough, it also supports add-ons which makes gedit even more powerful and useful.
Very versatile, it can highlight a good number of programming languages, among them we can highlight C, C++ Java, Python, Fortran, Haskell, SQL, PHP or Javascript.
It consumes very few resources, which makes it very useful if don't have a powerful computer or if you need to open several documents at once.
Finally, if the features included aren't enough, it also supports add-ons which makes gedit even more powerful and useful.
Gedit Command
Gedit Download
Gedit Cannot Open Display
By Beatriz Escalante