Google is celebrating its 10th birthday and lauding the success of its growing portfolio, but a 'beta' status still accompanies some of the web giant's most famous applications, such as Gmail, Google Docs and Google Finance.

The search firm has argued that this is because it adopts a different definition of 'beta' to other firms.

Google Docs was launched well over a year ago, and Gmail testing began as early as April 2004, but the firm maintains that the applications still need to undergo further engineering before they are fully released.

"We have a broad notion of what constitutes 'beta'," said a Google spokesman. "We do not tend to get hung up on beta as a stage. No one in the company keeps an overall track of what is in beta and what is not."

The spokesman dismissed any possibility of a connection between the beta status of Gmail and Goole Docs with problems users may have experienced with their Google accounts in recent months.

He claimed that the length of time Google applications are kept in beta is simply down to the amount of testing performed on the products, although this is only on products launched since its flagship Search, which was never officially in 'beta'.

"For example we re-engineered the back end of Gmail last year so that the code could be streamlined," he said. "And we are constantly working on things like lower outages."

Google stressed that, although it has an internal time line, a full release strategy for products will not be pre-announced.

The spokesman further dismissed possibilities that cloud applications can be fully released faster than traditional applications because they can be updated more easily, although he could give no reason as to why this is the case.

Instead, he issued a contradictory statement, putting forward Google's official line on the matter.

"On the web, you don't have to wait for the next version to be on the shelf or an update to become available," he said. "Improvements are rolled out as they are developed."