The Supreme Court of the U.S. has agreed to review the Bilski case discussed below. The Bilski case disavowed the controversial State Street Bank decision and severely limited the possibility of obtaining business method patents and put the validity of many into question. It also affects software patents that do not describe a lot of hardware, and, in fact, is relevant to all method patents.
The Bilski decision set forth a requirement that any process claim in a software patent must be tied to a particular machine or apparatus, or transform a particular article into a different
state or thing (“machine-or-transformation” test), to be eligible for patenting under 35 U.S.C.
§ 101.
The requirements for patentability of software has been in flux for 20 years. This History of Software Patents shows how attitudes towards software patents shift like a pendulum.