The appearance of NeXTStep desktops
on a Madonna music video
"?) gave millions of geeks
inspiration to drive
to their friend
's house to see a tv
for the first and last time
NeXTStep is arguably the most famous We're-Not-Worthy-Ware of the 1990s.
More recent products that tries to live up to NeXTStep's ideals: Macromedia Authorware, Borland Delphi, GNOME's Glade/KDE's KDevelop, IDE's for Java's Swing API, and the most universally praised yet humblest replacement--HTML based forms and the thousands of IDEs and editors that compose (you call this compose?) them.
How important is a good prototyping tool? NeXTStep development tools gave potential backers a revealing glimpse of the first prototype of the World Wide Web (made with the help of NeXTStep). Doom the shoot-em-up game was also developed with the help of NeXTStep.
Few computer users today disregard the awesome possibilities of coming up with a rapidly developed and usable prototype of their final product.
(See Perl, Tcl/Tk, Python, KDevelop/Glade or Linux if you want all of the previously mentioned tools to add a few quality prototyping devices to your workflow...)
If you must see one to believe it for yourself, visit the nearest University's computer science labs, they might keep a NeXTStep or OpenStep-based development workstation around for ol' time sake.
To keep your prototyping endeavors really simple and productive--if you don't program a lot--you can use a dirt simple prototyping and website-making tool call AOLserver (formerly known as NaviServer). It's a powerful, free and GPLed tool. (See ACS or www.photo.net/wtr to try something really ambitious with AOLserver) Another tool ready to surpass AOLserver in many ways is the Apache Web Server.