The group of activists, Stop Software Patents, claims the support of 80 companies, associations and developers, though its list of supporters lacks any of the software world's major companies.
On 24 September the group will launch its petition calling for a worldwide halt to software patents, which it claims damage the interests of businesses and consumers.
"Software patent regimes do not benefit the economy," the group's draft petition says. "Insufficient economic evidence supports an application of the patent system on software. On the contrary, most studies hint that software patent regimes restrain innovation."
The group claims that patent applications for software are written too broadly and generically. As such they are not of use to others hoping to emulate the invention – one of the purposes of patents – and allow a patent owner to claim rights over other people's inventions.
"Patents are broad shotgun rights, as opposed to precision rights such as software copyright," says the petition. "Broad, intricate and clumsy rights are damaging for the market but more valuable for their holders. 'Inventors' phrase their applications very broadly and negotiate with the patent office over breadth of the grant."
The activists' petition outlines some of the problems that they believe software businesses face because of patent law.
"Infringement is difficult to research as patent databases, software and patents are complex. You can easily violate hundreds of patents you are unaware of," it says. "Only courts can decide if you infringe a patent."
"Patent attorneys can do unreliable research for you. You take all risks and costs. You are forced to bow in to cease and desist letters about questionable patents or settle out of court as litigation is too expensive and takes ages. As a small player you can either pull or cut your software or take a license if available," it says.
Software patents are allowed in the US, where activists claim broad claims have been permitted in a manner which makes software development difficult. They also claim that patents are often awarded for technology which was invented by others in the past.
In Europe the European Patent Convention is interpreted differently in different countries. The European Patent Office is more likely than the UK Intellectual Property Office (UK-IPO) to award patents to software inventors.
UK legislation says that it is not possible to patent a computer program 'as such', meaning something which is only a computer program cannot be awarded a patent.
The Stop Software Patents Day celebrates amendments made to a European Commission by the European Parliament on 24 September 2003. The Commission had sought to harmonise Europe's patent rules, but the Parliament amended the plan to specify that patents would not be awarded for "actual software".