Dear Rafal, I'm developing a graphical tool to construct RNA 3D models. You can find all the details at this address: http://www.bioinformatics.org/assemble/
It is open-source. At now, i'm searching beta-testers before the official 1.0 release. If you're interested, I will send you an email explaining you how to download the tool. Best, Fabrice Jossinet -- Laboratoire de Bioinformatique, modelisation et simulation des acides nucleiques Institut de biologie moleculaire et cellulaire du CNRS UPR9002, Architecture et Reactivite de l'ARN 15 rue Rene Descartes F - 67084 Strasbourg
