One of the problems with British open source companies is that they're too damned modest. Unlike their American cousins, they tend not to shout about their successes from the rooftops. As a result, they often go unnoticed by the wider business world until one day, someone has an epiphany, and discovers that their needs can be met perfectly by free software that just happens to be made in the UK.
Openads is a case in point: it's a London-based company that no one seems to have heard of, and yet it has a free product that many companies could benefit from, given that it's advertising that currently makes the Web go around:
The Openads adserver is a free Open-Source adserver which you can download and install on your server of choice (see documentation for server requirements).
You can use it to manage banners of as many different types of ad networks (or self made banners) as you like across as many websites as you like. It provides options for banner capping, user & site based targeting, time or impression/click limited campaigns, and prioritization of campaigns.
You can review the statistical performance of a specific banner, campaign, advertiser, publisher or zone and re-prioritize your banners as needed.
As well as offering increasingly-popular products - “Tens of thousands of people around the world have turned to our free ad serving software” the site says – the company also has some seriously un-British financial backing, including a recent hefty second round of funding. Perhaps it should spend a little of it on some decent marketing to get the message out....