This week, Microsoft is expected to announce subscription prices for all its software, a move aimed at application service providers.
Companies won't be able to get such rental pricing directly from Microsoft, but Microsoft executives have said they believe subscriptions will become increasingly prevalent, especially for productivity applications.
Over the next few years, software vendors will increasingly promote subscription-type licenses, analysts predict.
Software licensing is changing in other ways, too, with per-processor licensing on the rise and many new pricing models emerging.
"What vendors are looking for is more predictable licence revenue," said Marie Reeve, an analyst at Gartner Group. "A lot of users skip versions [of Office]. Microsoft is not seeing revenue from those customers in that period of time."
Meanwhile, other factors could further complicate software licensing. Microsoft's recently announced .Net strategy foresees a world where an application - hosted or on a corporate network - is built up out of building blocks, some of which may be hosted somewhere else on the Internet. It is unclear how these building blocks will be paid for.