Opera the Browser may not be a household name in the United States, but around the world it's wildly popular and on the company's 15th birthday things are moving in directions the founders may never have expected.

The company marked its big day with an awesome throw-back version of its home page and a press release reminding everyone just how far it's come.

Opera is used by 40 million people, the company reports. That may be a relatively small community as browsers go, but it's a very, very loyal group and the company reports that it is growing fast. Mobile use just saw a 157% increase year over year, Opera announced yesterday.

From the original "speed dial" to built-in Torrent support, Opera has been as innovative as it has been standards-based. Håkon Wium Lie, now the CTO of the company, was one of the key inventors of CSS.

The big win for the company has, of course, been in mobile browsing. Before Safari and the iPhone, Opera Mobile was without a doubt the best mobile browser on the market. The iPhone is only a portion of the mobile market and Opera remains strong on many other phones, including default status as the browser on several Windows Mobile phones. Now, Opera has come to the Nintendo Wii, automobiles (it just got added to Ford Trucks for example), and countless other devices. For the first time in its history, the now 700 person company is planning a major advertising push - so, if you haven't thought much about Opera before, you may be hearing a lot more about it soon.

Opera is cool. We don't use it here at ReadWriteWeb because we love our Firefox plug-ins, but we sure are happy to see the company thriving and innovating 15 years after its birth.