[Nix-dev] Suggestion: programs are *always* in the path

[regivanx at gmail.com]

Hello!

If you enter a command, you want to run it.

If the corresponding program is not installed, the command is a symbolic 
link to a script that says:

_ download the program and its dependencies,
_ install it,
_ run it.

The speed of installation and execution is optimal because the script 
already knows what to download and install.

This comes close to how web applications are downloaded and executed. To 
run a web application, you enter its URL in the address bar and the 
browser automatically takes care of downloading it, installing it in the 
cache and running it. This system should also exist for local programs.