Google is also partnering with software and software-as-a-service vendors to develop Google Search Appliance plug-ins for applications Oracle, Microsoft Exchange, and Salesforce.com.

With some 200 Australian companies wanting to evaluate the appliances, according to Google, the first units arrived in the country this week and at least one unit has already been sold.

While the boxes run a modified version of Linux, only the source code for the modifications Google makes to the open source software will be released and not all of the appliance's code.

The Google Search Appliance can index up to 15,000,000 documents, and begins at A$74,486 (US$55,000) for up to 500,000 documents. The Google Mini starts at A$4965 for up to 50,000 documents - including hardware, software and a year of support.