The case is being brought against the search and advertising giant by Northeastern University and Jarg.

Jarg, co-founded by a Northeastern professor, is the exclusive licensee of the patent in question: US patent 5,694,593, "Distributed computer database system and method", filed in October 1994 and granted in December 1997.

So far as this writer can understand it, the patent describes a method of dividing a database search between multiple computers, each accessing a partial copy of the database, and then assembling the partial results.

Northeastern and Jarg claim that Google's search engine works in a manner that infringes the patent.

Google was founded in 1998 as the result of a Stanford University research project begun by Larry Page and Sergey Brin in January 1996 - after patent 5,694,593 was filed.

According to reports, Google officials say the case is "without merit". This could mean that the company's systems do not operate in a way that infringes the patent, or that it believes the patent is invalid for some reason such as 'prior art'.

Jarg was advised by an undisclosed law firm over two years ago that Google might be in breach of the patent but needed to find a firm that would take the case on a contingency basis, according to The Boston Globe .

The suit has been filed in the Texas Eastern District Court, a venue considered favourable for patent holders. Over 800 patent infringement cases have been filed with the court during the last three years,

The claimants are not seeking to prevent Google from using the patented method, but they are seeking backdated and ongoing royalties that Google has presumably declined to pay.