Contains, as a main contribution, a function to fit a regression model with possibly right, left or interval censored observations and with the error distribution expressed as a mixture of G-splines. Core part of the computation is done in compiled C++ written using the Scythe Statistical Library Version 0.3. The methods implemented in the package have been published in Komárek, Lesaffe and Hilton (2005, J. of Comp. and Graph. Stat.) <doi:10.1198/106186005X63734> and Lesaffre, Komárek and Declerck (2005, Stat. Methods in Med. Res.) <doi:10.1191/0962280205sm417oa>.