Nuendo is a professional digital recording and mixing program. In 1999, the German company Steinberg (www.steinberg.net) programmed Nuendo to be a recording and mix program for a quad processor IRIX machine. They found out, at a trade show that SGI was discontinuing the machine Nuendo was programmed for. Oops. They went back and ported it to the X86 architecture and Windows platform, then to the Macintosh later. Cubase owes its orgins to Nuendo, as the interfaces and core components are very similar.
The software was quite well designed at the outset, so the current version of 1.52 differs very little from 1.0 for IRIX. The UI has hardly changed. The program has become significantly more compatible with external mixing boards and various input devices, including MIDI. A version 2.0 release is expected sometime in 2003, and will cost about 1500 dollars. Version 2.0 updates various components and provides a host of new compatibility features, including more surround options. 2.0 is also supposed to be better integrated with other media formats.
User Interface
I shall assume that you, the reader has some basic knowledge of a recording studio. Nuendo is a complete digital studio, it emulates almost all of the equipment usually found in analog equipment racks. Nuendo separates functions into various windows. This allows the user to close windows that aren't being used. You don't really need the record window when gating a track.
Windows/Tools
The windows are very similar to their analog equivalents. there is a track display window with faders. It operates just like the faders on a mix board. The EQ, FX and Send controls are in a different window. There is an EQ button one pushes to open this window. Here, all the cool stuff happens. Four state EQ and all the FX controls are here. Eight send controls can be set to various effects.
All of the plug ins have their own window, much like the front panel to a rack mounted device. These plug ins come in many forms. All the standard ones are included, such as gates, reverb and delay. Many companies provide other plug-ins, like noise or vinyl distorters.
Instead of an analog tape machine or DAT machine, there is a project window. This window displays all the tracks in a visual sine wave format. The effects and EQ window can be accessed from here as well.
Compatibility and devices
VST is the plugin standard that Steinberg products like Nuendo and Cubase VST use. Many other programs use the VST standard. The VST plugin graphics look remarkably like their analog IRL counterparts.
ASIO drivers are used for many devices. Many different mix boards can be used, along with keyboards and samplers. OMS, the open MIDI protocol is supported.
Recording
Nuendo supports audio recording as well. One can record an unlimited number of channels. Other parts of the system limit recording. Most sound cards cannot support more then 8 channels of input. Also, even a dual Pentium 4 Xeon machines cannot support more then about 60 channels of input at once.
The Mix and Signal Flow
Nuendo, like Pro Tools, is a complete studio tool. Through VST plug-ins, almost everything possible in an analog studio is possible in Nuendo. As in a regular studio, everything can be done in real time. Real time effects are limited by processor speed.
Sources: Personal experience with version 1.52 for the Macintosh. John Barsotti's sound engineering course, which I had the pleasure of auditing. If I missed anything, please inform me so I can fix it.