Having been around the Mac world for a number of years, I'm always sad to see a venerable company decide to close up shop. The latest is Circus Ponies, the company with a whimsical name and logo that produced the NoteBook app.
The NoteBook app was originally written in 1991 for the NeXT machine (for those of you who are new to the world of Apple, NeXT was the company started by Steve Jobs after he was ousted from Apple). At the time, NoteBook was so revolutionary that it won NeXTWORLD Magazine's 1991 App of the Year award. When Steve Jobs returned to Apple, NeXTStep -- the Unix-based operating system of the NeXT machines -- became the basis for OS X... and iOS, watchOS and tvOS.
NoteBook was rewritten to run on OS X, making its first appearance in 2003. It was a surprisingly powerful note-taking, project managing and organizing app. An aside on the Circus Ponies site says that "Microsoft cloned NoteBook in the early 2000s to create the craptacular OneNote." The app was also ported to the iPad in 2010.
No reason was given for why the company is closing, but we're sad to see that the ponies are gone.