Let’s welcome the drjekyll gem that includes a command line tool, that is, drjekyll that lets you manage static site theme packages. For example, use:

$ drjekyll list     # or
$ drj ls

to list all 100+ themes e.g. resulting in:

  1..Henry's Starter (Minimal) (starter | henrysstarterminimal) by Gerald Bauer - #white
  2..Henry's Minimal (minimial | henrysminimal) by Gerald Bauer - #white
  3..Henry's Bootstrap (bootstrap | henrysbootstrap) by Gerald Bauer - #bootstrap #sass #white
  4..Henry's Classics Book (classics | henrysclassicsbook) by Gerald Bauer - #books #white
  5..Poole (poole) by Mark Otto - #poole
  6..Poole's Hyde (pooleshyde) by Mark Otto - #poole
  7..Poole's Lanyon (pooleslanyon) by Mark Otto - #poole
  8..Beautiful Jekyll (beautifuljekyll) by Dean Attali

To download and unzip a theme archive use the “installation code”, for example, use:

$ drjekyll new starter   # or
$ drj new starter

to dowload and unzip the Henry’s Starter (Minimal) theme and so on. For more info see the drj/drjekyll project site. Cheers.