Mateusz Loskot wrote :
Today, my friend was told (warned) on the #c++ IRC channel that Boost uses some technologies already patented by IBM (and may be other entities), like RCU or SMR (and may be more).
I think I saw part of that discussion. It actually started about the cost of reference counting in multithreading environments. Then it was said that using technologies such as RCU and SMR could improve performance, but given that those are patented [1], they couldn't be used in boost::shared_ptr. I do not know how this discussion transformed into patents being used in boost though. Since I don't really know myself how RCU and SMR work, I am unable to give more info but if you're interested you could search for "RCU SMR" in Google groups which seems to bring interesting results in comp.programming.threads and comp.lang.c++.moderated about this kind of stuff. [1] It seems, though, that IBM has authorized the use of RCU in GPL'ed software.