Windows only: AnVir Task Manager Free is a Windows Task Manager replacement boasting an enormous feature set. This utility can manage startup applications, running applications, processes, services, and oh-so-much more. When you select a running process in the top pane, the bottom pane provides a wealth of information about the process, from a brief description of what it does to the network connections it's making and DLLs it's using. One of my favourite unusual features is the Check with AntiViruses on VirusTotal right-click option—which streamlines my favourite method of determining if a file really has a virus. You can find tons of Task Manager replacements out in the wild, but AnVir still manages to stand out. If you want even more functionality, this free download is also available in a Pro version with a kitchen sink full of features.