Bill Gates will step down on Friday from the company he founded back in the ’70s, leaving it all to Steve Ballmer, Microsoft’s CEO, and Ray Ozzie, its chief software architect. So let’s say a few words about the man that has been Microsoft’s face for over thirty years.

Bill Gates has been loved by many, and hated by many also, but I guess that’s just the faith of every enormously influential man. One thing that nobody can deny is the fact that he is the one who shaped the IT industry into what it is today. Even if the concepts that the Microsoft empire has been built on have been discovered by others before Bill Gates, and even if he sometimes bought companies that were making revolutionary products instead of creating them himself, he is the man that knew how to bring them to the public’s attention.

It was in 1975 that Bill Gates and his friend Paul Allen have contacted Micro Instrumentation and Telemetry Systems (MITS), which has just developed the Altair 8800, to write a BASIC interpreter for the platform. The two made a demonstration at MITS’s headquarters which determined the company to hire them to make the interpreter. It was with this occasion that Gates and Allen started thinking of making their own company, which they registered in 1976 under the mane of Microsoft.

Their first big hit came as the company was contacted by IBM to make a BASIC interpreter for the personal computer that they were about to release. It also asked Gates to recommend them an operating system for the computer. Microsoft managed to become the full owner of the 86-DOS operating system that was developed by another software company and after making a few changes to it sold it to IBM under the name of PC-DOS.

The smart move that Gates made with this occasion, and the one that probably changed the course of Microsoft’s entire history, was to determine IBM to allow Microsoft to keep the copyright of the product. Since IBM’s PC architecture started to be imitated by others, Microsoft made a fortune by selling licenses of its PC-DOS operating system to all these companies.

Another major breakthrough for Gate’s company has been the development of the Windows platform, which could be regarded as one of the most important factors that influenced the course of IT industry, by bringing a more graphical approach to PC usage, which made the masses adopt it easier.

Bill Gates reached the peak of his wealth in 1999 when he was worth about $101 billion. Since then his fortune dropped a few billion dollars partly because of Microsoft share price falling and Gates making more and more donations to different foundations. According to Forbes, he has been the world’s richest man from 1995 to 2007.

It will be interesting to see what will happen to Microsoft now that he is gone. Even though some people predict that the transition is going to be done smoothly, and that Microsoft is now less dependent of Gates’s image as it had been in the past, both Vista’s lack of success and Google and Apple coming fast from behind, might give the impression that the company needs Gate’s managerial genius more than ever.