The long-in-tooth software Magic Workstation (MWS) has received a patch for Mirrodin Besieged (MBS) courtesy of the folks of MTGSalvation (MTGS), specifically the forum mod 'Memnarch.' If you use Magic Workstation, then follow the link below for the file and instructions on adding Magic's latest expansion to the application.

Mirrodin Besieged Patch for Magic Workstation (155/155)

Alternatives to Magic Workstation

There are many alternatives to MWS when it comes to deckbuilding, from websites like our friends at TappedOut.net, to other desktop and phone applications which aim to help you with your deck building. There are even options when it comes to playing online, though MTGO remains the only officially licensed software to use for those such games. A useful website is SlightlyMagic.net forums which covers MWS as well as many other applications out there.