Companies with slow websites, be warned: Poor Web page load times might affect how those pages rank in Google searches.

Google noted this in a blog post on Wednesday marking the transition of its open-source mod_pagespeed software from beta status to official release. "[P]age speed is one of the signals in search ranking and ad quality scores," said software engineer Joshua Marantz and developer advocate Ilya Grigorik.

The software is an Apache server module that helps accelerate the delivery of Web pages.

Google has made speed in its various forms--Web page load time, network latency, software responsiveness--a priority for years, knowing that users abandon websites and software that perform poorly and that fast response times correlate with better user satisfaction, engagement, and monetization.

[ Read Google Declares War On Slow Web Pages. ]

Google launched mod_pagespeed two years ago in an effort to automate the speed improvements available through the use of its Page Speed tool. The software module helps reduce the load times of Web pages served by Apache Web servers by optimizing caching, reducing client-server round trips, and minimizing file sizes. The company claims mod_pagespeed can reduce page load times by as much as 50%.

The module is used by over 120,000 websites, according to Google. It's available to customers of Web hosting companies such as DreamHost and Go Daddy and content delivery networks such as EdgeCast and Contendo.

Google also offers speed as a service: Its PageSpeed Service fetches content from client servers, restructures the content to accelerate delivery, and makes it available around the world from its own servers. In addition, the company offers other tools to assess and evaluate Web page performance, such as its Google Analytics Site Speed Reports, PageSpeed Insights, and PageSpeed Optimization products.