IBM joined Microsoft and Google as a contender in the cloud software market, the company announced Dec. 6. IBM's SmartCloud Docs includes web-based apps similar to those found in Microsoft's Office 365 and Google Apps for Business that allow enterprises to share and collaborate on documents, spreadsheets and presentations.

The release from IBM comes at a time when cloud computing shows no sign of waning in popularity: Forrester predicts the $41 billion market will expand to $241 billion by 2020.

Alistair Rennie, IBM's general manager for social business, told Information Week, "As the mobile workforce moves beyond gaining access to email and calendars to collaborate and generate new ideas and be more efficient anytime, anywhere, on any device, the intersection of social, mobile, and cloud becomes even more critical."

IBM SmartCloud is available for $3 per user per month, as an extension of the SmartCloud Engage Standard and the IBM Connections networking platform. By comparison, Google Apps for Business begins at $5 per user per month, and Microsoft Office 365 starts at $4 per user per month.