Any review of the major technology developments of 2009 would inevitably include copious copy on the Googles, Microsofts and other giants of the tech world.

But it was also a year in which the tiny company called Twitter became a major communications force, and when political, economic, social and technological trends combined to put green technology at the forefront of innovation.

2009 was the year when the microblogging site Twitter became the de rigueur mode of communication for any artist, politician or celebrity who wished to display a cutting edge sense of connectivity.

But it also became an essential mode of communication for everyone from grandmas to schoolgirls, from company spokesman to revolutionary ideologues.

The uprising against the election results in Iran in June gave the most concrete indication to date of the power of Twitter to influence world events. As the Iranian government clamped down on other media and internet channels, Iranians kept taking to the streets and transmitting their experiences via the microblogging site, helping their leaders organize demonstrations, and sympathisers around the world keep track of their struggle.

The technology allows users to post instant and frequent updates via their mobile phones, and grew exponentially this year to an estimated 18 million users a month — a 200 per cent increase over the year before.

Giants get some competition

With the continued proliferation of the iPhone and its would-be competitors, Twitterers and others certainly had a huge variety of devices to choose from.

Though Apple’s iconic device remains the undisputed king of the sector, 2009 saw the emergence of its first credible challengers.

This was largely due to the emergence of Google’s Android operating system, which was adopted as a mobile platform by a growing band of device manufacturers, notably Taiwanese maker HTC, and Motorola, a once-dominant handset maker which is banking its future on Android.

Though the global recession cut into Google’s amazing growth spurt and even prompted it to announce its first firings and cost-cutting initiatives, Google still dominated the Internet search market throughout the year. It still registers some 60 per cent of all U.S. searches, but now, when the company executives look in their rear view mirror, they might notice the tiny image of a distant giant approaching.

After years in which Microsoft botched every attempt to build on the dominance of its Internet Explorer browser, the Seattle software giant has finally got something right with its Bing search engine.

The company’s heavily-promoted new technology has been warmly reviewed and has grabbed a 10 per cent market share since its launch.

Microsoft’s agreement to provide Yahoo! with its search technology and its discussions with news providers for exclusive contracts could yet make it a formidable Google competitor.

Windows 7 launched

Microsoft also finally got it right with the release of its Windows 7 operating system less than four years after it launched the widely-derided Vista. According to Microsoft, the new software has sold more than twice as many copies as Vista did during its initial launch period. The October release also helped pump up computer sales for the crucial holiday season.

Green tech gets a boost

But perhaps the biggest technology story of the year revolves not around the latest computing innovations but on the ever-increasing focus placed on the development of clean green technology. According to tracking firm CleanTech Ventures, U.S. clean technology venture investments totalled $1.59 billion in the 3rd quarter of 2009 for the second consecutive quarterly rise after steep declines prompted by the global recession.

Green industry got an added boost from the U.S. government this year under U.S. President Barack Obama’s stimulus programme, which set aside nearly 10 per cent or $70 billion for energy efficiency and new methods.

Huge investments have been made from outside the venture and government scene. ExxonMobil for instance has pumped $600 million into a San Diego-based scheme to develop fuel from algae, while two California-based companies have received almost $1 billion in government awards to develop electric cars.

Private investors were also eager to open their wallets as they sought to take advantage of low share prices for emerging technology firms. But while 2009 was a year of recovery for green technology, 2010 is likely to see a return to significant growth as high oil prices and the focus on a low-carbon economy continue to fuel interest in alternative energy.

“Bring me your business plans,” venture capitalist Steve Westly told a tech industry conference in November. “We are ready to start funding again.”