After the NeXT Purchase
Apple bought NeXT to acquire its operating system, and let a lot of NeXT's other technologies die. The OpenStep development environment was originally available for OPENSTEP (NeXT's operating system), Solaris, and Windows NT. Early presentations by Apple showed OS X containing Blue Box (the legacy Mac OS layer) and Yellow Box (the OpenStep environment that later became Cocoa). Apple also discussed Yellow Box for Windows, an updated version of the OpenStep environment on Windows NT. Developing this version would have made it trivial to port native OS X applications to Windows.
WebObjects was largely ignored by Apple, which used it internally for the Apple Store and the iTunes Store. After a few years of failing to work out how to make money from WebObjects, Apple bundled it for free with the Xcode developer tools. If you've installed the developer tools on your Mac, odds are that you have WebObjects installed. In spite of this implementation, however, WebObjects isn't very widely used.
NeXT built very expensive computers, with no need to worry about backward compatibility, and with the freedom to cherry-pick the best ideas from the rest of the industry and from research communities. The systems NeXT built were incredible, giving other companies something worth copying.