As you may now by now, this month had passed out three important figures in the Computer Science world: Steve Jobs, Dennis Ritchie and John McCarthy.
Steve Jobs is the most famous of them by the general public, but, at the same time, the less influential in the Computer Science world. His most important achieve has been to change the perception and use of the technology of a lot of people. He was capable of innovate and connect with the general public, but, in my point of view, he was wrong about oe essential thing, the openness of his products. During all his career, and specially during his last years, he has managed his products in a closed way (he even didn't want to open the apple market to independent developers!) and I think he has missed the opportunity to really change the world if he would made free (as in freedom) at least any of his products.
Dennis Ritchie, as many of the articles has said about him, is one of the original hackers. His great contribution (with other hackers) to our world include the C programming language (probably the most used programming language of all the times) and the Unix Operating System (the same used by apple to develop Mac OS and used as a reference by Richard M. Stallman and Linus Torvalds to develop GNU/Linux). This is a perfect example of how a free software can influence in the world (remember that Unix, at the beginnig, was open, and was after its success when companies and organizations started to launch his own closed version of Unix).
The last one that have passed out is John McCarthy, creator of the Lisp programming language and of the term Artificial Intelligence. The Lisp programming language is less used than the C programming language, but it has been the most used programming language in Artificial Intelligence, in wich he is one of the major contributors. He also was the first to publicly suggest that computer time-sharing technology might lead to a future in which computing power and even specific applications could be sold through the utility business model.
We're going to miss them and we'll try to continue their work the better we can.