Unsupported VRPN, No License Fees
The Virtual Reality Peripheral Network (VRPN) is public-domain software released by the Department of Computer Science at the University of North Carolina at Chapel Hill. Its development was initially supported by the National Institutes of Health National Center for Research Resources program and is currently provided by the National Institute of Biomedical Imaging and Bioengineering. UNC's center for Computer-Integrated Systems for Microscopy and Manipulation provides free, as-is, unsupported releases of this software. Instructions for downloading this software are found at www.cs.unc.edu/Research/vrpn/obtaining_vrpn.html. As described there, individuals and groups are welcome to download and use VRPN without license fees.
Current documentation available about VRPN is found on the VRPN web page (a copy of which is included with each release; the latest version can be found at www.vrpn.org). A paper describing VRPN was presented at the VRST 2001 conference. A reprint of the paper can be found here. A copy of the Powerpoint presentation can be found here.
There is a VRPN Redmine project management site that you can register for to add bug/feature requests for VRPN.
VRPN Support by Developers and Users
The developers of VRPN are continually improving the system and adding features to support their own research. These improvements are added into the public-domain version as new releases. Outside users of VRPN often add new features and devices, and are encouraged to feed these improvements back to UNC so that they can be included in future releases. This has two benefits: the group feeding back the techniques benefits because the changes are automatically carried to future releases and the entire community benefits from the addition of the new features.
If you are wondering whether a feature you want is coming soon, searching the archives at http://lists.unc.edu/read/?forum=vrpn and then sending an email to firstname.lastname@example.org is often a fruitful way to determine this (if you use VRPN, you are encouraged to be on this mailing list, which is also used to announce new releases and other items of interest to VRPN users). You can add yourself or remove yourself from the list by visiting http://listserv.unc.edu and using the Search for Lists Tool to find vrpn, then subscribing using the button. Questions to this list are answered as time permits.
Paid VRPN Support
For those wanting more reliable support, email to email@example.com provides fee-for-services support for VRPN. The intent is to widen the usefulness of VRPN while recovering the costs of supporting projects other than UNC research. This support has taken several forms, including:
This support is normally provided on an hourly, fees-for-services basis. Free estimates of the cost for particular enhancements and bug fixes are available. Fixed-rate, fixed-duration support contracts are also available if these are more appropriate for your needs (yearly or semester-long support contracts, for example).
The paid enhancements have been wrapped immediately back into the public-domain versions and released for general use. The feature enhancements in versions 4.07-5.00 and 05.02 of VRPN were enabled in whole or large part by industrial support from the Walt Disney VR Studios. Versions 05.01-05.02 were supported by Schlumberger Cambridge Research. Version 07.32 was supported by Sensics and YEI. This policy allows the entire community to benefit from the support, while still allowing the client to get features they need in a timely manner. VRPN is happy to list the names of supporting individuals or groups, but in order to preserve privacy we will not do so unless you request it.