Utilizing different drush versions
Sometimes you need to use a different drush version on your project.
You may use the alias method, for example:
alias drush5="~/bin/drush-5.4/drush"
Where in this case you unpacked drush-5.4 archive/source-files inside the bin
folder on your site's remote directory.
With this alias, you can call drush5
to load this specific version of drush via shell.