Initially, iPhone Dev Team has released Command Line Interface (CLI) for Corona A5 jailbreak for Mac and now the tool is available for Windows as well.
See also:
Command Line Interface for Corona A5 Jailbreak Released
GreenPois0n Absinthe Untethered Jailbreak Tool for iPhone 4S and iPad 2
How to Do Untethered Jailbreak iPad 2 over iOS 5.0.1 with Absinthe
How to Do Untethered Jailbreak iPhone 4S over iOS 5.0.1 with Absinthe
Jailbreak with Command Line Interface (CLI) for Corona is tricky so its recommended for expert users only. To jailbreak iPad 2 or iPhone 4S with CLI and to know details about tool head to source.