2700 Billion Digits of Pi
On December 31st, Fabrice Bellard (founder of FFmpeg) announced that he’d calculated pi to 2,700 billion decimal places. Check out the details here. The coolest thing is that he did it using a single processor PC. Instead of throwing lots of expensive hardware at the problem, he worked on optimizing the software side. For very large variable precision numbers I/O becomes the bottleneck because you can’t keep them in memory. The run took a total of 116 days. He provides plenty of juicy details here and some samples of the digits here.
In related news, HP appears to have gotten a patent on one of the basic techniques used in this sort of computation, even though Knuth describes it pretty thoroughly in the second volume of The Art of Computer Programming.