Since its launch in 2006, Google Apps - the office applications set delivered as a service over the web - has been hugely popular among small firms and individuals. But in recent months a growing number of large companies have been signing up, despite some apprehension around security and availability. The attractions for CIOs include increasing functionality, cost savings and the ability to access data from any location. As a result, many commentators believe Google is becoming a force to be reckoned with in enterprise IT. Here are some of the biggest early adopters:

Rentokil Initial

The pest-control, courier and business services multinational is embarking on the biggest single deployment of Google Apps to date. By the end of 2010, it is scheduled to replace 180 different email domains used by up to 35,000 - largely mobile - employees in 50 countries. CIO Bryan Kinsella says he has overcome earlier concerns about data security and archiving.

Essilor

The French optical equipment maker employs nearly 30,000 people in 100 countries. CIO Didier Lambert, struck by Google Apps' capacity for global collaboration and data access, has committed to a wholesale rollout.

City of Los Angeles

The US's second-largest city will migrate 30,000 employees to Google Apps during 2010. One of the attractions was Google's planned development of a private "Gov Cloud", due this year, to accommodate the security concerns of public-sector organisations.

Jaguar Land Rover

After it was sold to Tata Motors, the car maker had to extract 18TB of emails from Ford's Microsoft Exchange system, so it migrated 14,500 staff to Google Apps. Moving old emails into Gmail was "complex" but saved "several million pounds", says CIO Jeremy Vincent.

JohnsonDiversey

In mid-2009, the global provider of cleaning products migrated 12,000 global users from Lotus Notes/Domino to Google Apps.

Data feed

• Google claims more than 2 million businesses with 20 million users subscribe to Google Apps.

• According to a survey by IDC in September 2009, Google Docs is "widely used" in one in five workplaces. IDC has also forecast 30% year-on-year growth in enterprise demand for hosted applications over the period 2007-11.

• Microsoft predicts that 20% of email seats in large enterprises will be delivered via hosted email by 2014.