NewsGator has agreed to acquire NetNewsWire, a Mac-based news reader. 

NetNewsWire has a strong following among early Really Simple Syndication (RSS) users on the Mac OS X platform, but is facing increased competition now that Apple has included support for the syndication technology in OS X 10.4 Tiger. 

Penetration of RSS on the Mac is relatively high, according to Greg Reinacker, founder and chief technology officer at NewsGator.

"That gives us a unique opportunity to try out new leading-edge stuff with [Mac users]," he said.

RSS has emerged as a tool that notifies users when new content is published on a website. The technology was made popular by blogs and news websites, but is still in its infancy.

Analyst firm Forrester Research estimates that only two per cent of the internet population uses the technology.

NewsGator offers an online news reader and a plug-in for Microsoft Outlook. Earlier this year the company acquired FeedDemon, a developer of a Windows RSS reader client.

In addition to a basic free service, NewsGator offers several premium services including the Outlook plug-in and an email notification service.

The addition of NetNewsWire makes NewsGator the world's largest RSS provider, Reinacker claimed.

The RSS technology is expected to gain further appeal with the release of Internet Explorer 7.0 next summer, which will include support for the technology, as will the forthcoming Windows Vista.

VNU, the parent company of vnunet.com, has a partner agreement with NewsGator for the distribution of its web-based service in Europe.