<legal> A patent intended to prevent others from using some programming technique. There have been several infamous patents for software techniques which most experienced programmers would consider fundamental or trivial, such as the idea of using exclusive-or to plot a cursor on a bitmap display. The spread of software patents could stifle innovation and make programming much harder because programmers would have to worry about patents when designing or choosing algorithms. There are over ten thousand software patents in the US, and several thousand more are issued each year. Each one may be owned by, or could be bought by, a grasping company whose lawyers carefully plan to attack people at their most vulnerable moments. Of course, they couch the threat as a "reasonable offer" to save you miserable years in court. "Divide and conquer" is the watchword: pursue one group at a time, while advising the rest of us to relax because we are in no danger today. Compuserve developed the GIF format for graphical images many years ago, not knowing about Unisys's 1985 patent covering the LZW data compression algorithm used in GIF. GIF was subsequently adopted widely on the Internet. In 1994 Unisys threatened to sue Compuserve, forcing them to impose a sublicensing agreement for GIF on their users. Compuserve users can accept this agreement now, or face Unisys later on their own. The rest of us don't have a choice -- we get to face Unisys when they decide it's our turn. So much trouble from just one software patent. Patents in the UK can't describe algorithms or mathematical methods. See also LPF, software law. {patent search (http://sunsite.unc.edu/patents/intropat.html)}. (1995-01-06)

A software patent is a patent on a piece of software, such as a computer program, libraries, user interface, or algorithm.

The software patent debate is the argument about the extent to which, as a matter of public policy, it should be possible to patent software and computer-implemented inventions. Policy debate on software patents has been active for years.

Software Patent Institute (established 1992 in Ann Arbor)Bernard Galler, University of Michigan Software Patent Institute is an American non-profit corporation established to assist in the correct assignment of software patent.www.

Neither software nor computer programs are explicitly mentioned in statutory United States patent law. Patent law has changed to address new technologies, and decisions of the United States Supreme Court and United States Court of Appeals for the Federal Circuit (CAFC) beginning in the latter part of the 20th century have sought to clarify the boundary between patent-eligible and patent-ineligible subject matter for a number of new technologies including computers and software.

The patentability of software, computer programs and computer-implemented inventions under the European Patent Convention (EPC) is the extent to which subject matter in these fields is patentable under the Convention on the Grant of European Patents of October 5, 1973. The subject also includes the question of whether European patents granted by the European Patent Office (EPO) in these fields (sometimes called "software patents") are regarded as valid by national courts.

The WTO's Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS), particularly Article 27, is occasionally referenced in the political debate on the international legal framework for the patentability of software, and on whether software and computer-implemented inventions should be considered as a field of technology.

A patent attorney is an attorney who has the specialized qualifications necessary for representing clients in obtaining patents and acting in all matters and procedures relating to patent law and practice, such as filing patent applications and oppositions to granted patents. The term is used differently in different countries, and thus may or may not require the same legal qualifications as a general legal practitioner.

A patent examiner (or, historically, a patent clerkThe title "patent clerk" is used for instance in Gary Stix, The Patent Clerk's Legacy, Scientific American, September 2004 (an article about Albert Einstein).) is an employee, usually a civil servant with a scientific or engineering background, working at a patent office.