Independent software vendor (ISV) is a term desribing software companies that specialise in designing and developing specialized software, designed for particular vertical or horizontal markets.  Such markets are very diverse and can include, Banking, Insurance, Retail outlets, Science, Engineering, Media, Service Management, Asset Management etc.

End user companies tend to buy off-the-shelf commercial software from ISV's wherever possible, to avoid having to develop the software in-house.  The end user companies benefit from being part of a community of similar companies using the software, where the community are effectively sharing the development and support costs.

The major IT companies encourage ISV's to develop software for their platforms because customers often select a package from an ISV then buy an appropriate platform to run the system on.  Microsoft, IBM, Sun, HP and Apple all have special programmes for ISV's. Sometimes the major platform suppliers also market applications in competition with ISV's,but in general, the platform providers do not have the resources or the agility to match the very large number of software applications marketed by the hundreds of thousands of ISV's.

Similarly, ISV's do not have all the resources to support all of the platforms and so, the ISV has to select one or more main platforms upon which to offer the software.