Well. GoboLinux solved that already. Back in 2005.
I never understood the real need for chruby rvm etc... - I manage everything, all programs, in a versioned AppDir manner. (Note: I am not using GoboLinux; I use a modified variant. GoboLinux gave the correct idea though.)
> each program in a GoboLinux system has its own subdirectory tree, where all of its files (including settings specific for that program) may be found. Thus, a program "Foo" has all of its specific files and libraries in /Programs/Foo, under the corresponding version of this program at hand. For example, the commonly known GCC compiler suite version 8.1.0, would reside under the directory /Programs/GCC/8.1.0
I never understood the real need for chruby rvm etc... - I manage everything, all programs, in a versioned AppDir manner. (Note: I am not using GoboLinux; I use a modified variant. GoboLinux gave the correct idea though.)