Best way to create archived/historic app versions

[eluser]tomcode[/eluser]
CI is pretty flexible and allows personalised system and application paths.
Additionally I got used to implement an asset path and a view path variable.
Sometimes I rename the application folder to the release name and number : domaine_XXX, sharing one common assets folder.
Sometimes I separate versions into different system folders.
The asset path and view path variables allow me further fine tuning for layout changes.