November 2005 of open source Berkeley Open Infrastructure for Network Computing (BOINC) software which powers projects such as SETI@home and Climateprediction. Mac OS and Linux support was added since the introduction of BOINC. In 2007, the World Community Grid migrated from Grid MP to BOINC for all of its supported platforms. In September 2021, IBM announced that it had transferred ownership of the World Community Grid to the Krembil Research Institute. The entire transition process will take place over the next few months. Scale of the project As of September 21, 2021, World Community Grid had over 33,000 active user accounts, with over 154,000 active devices. Over the course of the project, more than 2,000,000 cumulative years of computing time have been donated, and over 6 billion work units have been completed. Operation The World Community Grid software uses the unused computing time of Internet-connected devices to perform research calculations. Users install WCG client software onto their devices. This software works in the background, using spare system resources to process work for WCG. When a piece of work or workunit is completed, the client software sends it back to WCG over the Internet and downloads a new workunit. To ensure accuracy, the WCG servers send out multiple copies of each workunit. Then, when the results are received, they are collected and validated against each other. World Community Grid offers multiple humanitarian projects under a single umbrella. Users are included in a subset of projects by default, but may opt out of projects as they choose. Even though WCG makes use of open source client software, the actual applications that perform the scientific calculations may not be. However, several of the science applications are available under a free license, although the source is not available directly from WCG. Potential problems The World Community Grid software increases CPU usage by consuming unused processing time; in the late 1990s and early 2000s, such calculations were meant to reduce "wasted" CPU cycles. With modern CPUs, where dynamic frequency scaling is prevalent, increased usage makes the processor run at higher frequency, increasing power usage and heating counter to power management. Additionally, because of an increasing focus on power performance, or performance per watt, connecting old/inefficient computers to the grid will increase the total/average power required to complete the same calculations. The BOINC client avoids slowing the computer by using a variety of limits that suspend