i am using a vintage computer for my home use and to be frank i am satisfied with it since it is what i can afford now -- i use Ubuntu derived peer Linux OS and have gimp 2.8 working good and meets my needs. but due to the vintage configuration that i have it takes a long time to load and work but i need it for my little works related with educational helps - in most of the times i don't need my tweaked up gimp with all the plug ins and extra brushes i need a faster gimp so i want to have gimp 2.6 or even 2.4 in my system along with the current one. have pinta and like softwares but to meet my needs i definitely need gimp my question is can i have two different versions of gimp at the same time which i can load from the menu itself please help me thanking you all for allowing me breath the fresh air of open source --
Of course you can have two different versions of gimp installed at the same time.
The point to be noted here is that you DO NOT use the default package manager in your OS.
Instead, you have to download the installer files for the required versions and then install using them. Once you run the installer, it will ask you where to install the software. Provide different paths for the different versions. You can create soft-links from your desktop to the software executables for easy access.
In your case, since you have gimp 2.8 installed, get the installer for 2.6 and/or 2.4, and then install as mentioned above.