I think the Catznip viewer for Second Life™ has been around since about the time I joined SL, early 2008. Inara Pey has been covering viewers since before then. Her earliest article on Catznip, that I found, is September 2011. I suspect there were earlier ones. My earliest is February 2011, back when I was looking for the best viewer and doing reviews.
In my 2011 review I was noting that Catznip had not updated for about a year. At the time Catznip was not listed in the Linden’s 3rd Party Viewers list. It is now, as 1 of 8 full feature viewers.
Inara’s January 30, 2016 article notes it’s been about 18 months since the previous update. These long periods of inactivity are usually due to hardware or health issues. So, I doubt these long periods of seeming inactive denote any lack of motivation.
Inara has a good review of this newest Catznip Viewer (R10) release. So, I’ll send you there for the details. See: Catznip R10: the cat comes roaring back.
Kitty Barnett is the named author of the viewer. She is an SL resident since May 10, 2006, about 2 years before me. She is the owner of the groups; Catznip Viewer Litterbox and Catznip Viewer. The Catznip supporting web site is: http://catznip.com/. It is a wiki style site. The Catznip download link is on the home page.
The last version I played with was R7. So, I’ve skipped a couple of versions. R10 is still a 32-bit viewer. It has all same features as the current main Linden Viewer, I think. It is a V3 viewer interface. There are small differences between Catznip’s and the Linden viewer interface. But, changing between the two is easy. Stuff is pretty much in the same place, at least for the basic stuff I use.
I get 10 to 15 FPS with everything except DoF turned on. With other viewers I run 15 to 25 FPS with similar settings and in similar places. Jumping to a Linden landing hub with 33 avatars that drops to 8-9 FPS, which is not that bad. My Linden viewer and especially my FS drop frames much lower in a crowd. (Have you noticed more people at hubs are there to advertise stuff?) If I start camming around in Catznip, I can push it down to 5FPS.
I’m sure some people will be happy to see this new viewer out. I’ll play with it some to see how it does with RLV.