Why SN(oo)Py?

Okay, why the name?  Well, as is traditional with python packages, often the name starts or ends with 'py'.  PySN obviously just wouldn't do (if you can't think of why, keep thinking).  So, the next logical step was SNpy.  It's not too far from there to SNoopy (or snippy, or snappy).  If you like, the OO can stand for 'Object Oriented', which SNpy certainly is.  Lastly, SNOOPY as a whole acronym is actually already taken (IRAF package for doing... you guessed it... SN photometry).  So, I guess SNpy will do officially with SNoopy as an affectionate nickname.  Plus, that beagle is one handsome dude.

Why use it?

There are plenty of other light-curve fitters out there, so why do we need another? SNooPy came about because at the time I was working on the high-z component of the CSP, the existing fitters (SALT and MLCS2k2) could not fit photometric data in the NIR. Since then, more and more features have been added, mostly from requests of colleagues who aren't even working on SNe Ia. Some like to fit light-curves with the non-parametric fitters (splines, GPs, etc). Some like to use the filter/spectrum modules to do synthetic photometry. Some like to use the k-correction code with non-Ia SED templates. 

And it never hurts to have more than one way to do your science.