For instance, Norway's largest online newspaper Verdens Gang (vg.no) will soon be able to run their entire web site on two servers, where they previously needed 13 servers.

What does Varnish do?
Most web sites present dynamic web pages consisting of a number of different elements. Combining these elements is both time-consuming and CPU intensive, and the process is repeated for every individual user, even though the content is often identical.

Varnish temporarily stores the most frequently requested pages in cache memory. Presenting these pages from cache is very effective.

As a consequence, users are offered an improved service, and server requirements are reduced by up to 90 percent. Varnish also offers useful tools for identifying which pages should and should not be cached, and if they are cached, when to delete them and present fresh content.

Hand in glove for emergencies
You may also use Varnish to help solve acute web site performance problems, obtaining positive results without even customizing its configuration.

Who developed Varnish?
Varnish was developed for VG Multimedia by Norwegian company Linpro and Danish independent consultant Poul-Henning Kamp.

Varnish is Open Source, distributed under a 2-clause BSD license, allowing anyone to download and use the source code for free.

If you want professional support, Linpro offers installation, integration, housing and support. Linpro can also customize and expand the existing Varnish version to your needs and requirements.

See also http://www.varnish-cache.org