I just released version 4 of the GURPS Ritual Path Magic Designer web application (
http://gurps-monsterhunters.appspot.com/).
It fully supports the rules in GURPS Thaumatology: Ritual Path Magic and outputs your own rituals in the same format as that book.
New with this version is the ability to type directly into the Modifier fields instead of clicking the + and - buttons.
Those fields support a fairly lenient syntax - you can type 2000 lbs, 2000#, 2000 pounds, or 2 tons for subject weight, for instance.
Many of the fields support multiple conversions - Duration, for example, supports minutes, hours, days, weeks, months, or years with full conversions between units. For example, you can type in 24 months, 104 weeks, 730 days, 17520 hours, or 1051200 hours, and the app will convert any of those to 2 years.