For non-HL7 software the two most used utilities are JWepGen and JMd5Sum. As always, browse the navigation to the right for more information.
JWepGen is a platform independent WEP (128 or 64 bit) generator that matches the key generator algorithms that a number of popular implementations use. The webstart install will give you the option to install the software for use when you’re not online (which is when you must need a WEP generator). Note that WEP is generally considered insecure and WPA2 or something similar should be used if possible.
JMd5Sum has a simple GUI to help you generate MD5 and SHA1 sums of files. Any unix has similar command line utilities but if you prefer a GUI or work on some other platform this may be a convenient choice.