NP-hard problems (Non-deterministic Polynomial-time hard problems) are those problems which are not easier than any problem in NP; in other words, an algorithm for an NP-hard problem can be used to solve any problem in NP by transforming the input in polynomial time. Problems which are in both NP-Hard and NP are known as NP-Complete.

RELAX NG (ISO/IEC 19757-2) is an International Standard schema language for XML. A RELAX NG schema specifies a grammar that a validator can apply to XML documents to determine whether or not they are schema-valid.

Apache log4cxx is a logging framework for C++ patterned after Apache log4j. Apache log4cxx uses Apache Portable Runtime for most platform-specific code and should be usable on any platform supported by APR. Apache log4cxx is licensed under the Apache License, an open source license certified by the Open Source Initiative.

LNK2001 is a common Visual Studio linker error condition indicating that the linker is unable to locate or find the symbol being referenced. Check the SO post on common errors and their resolution.

Stereoscopy refers to a technique for creating or enhancing the illusion of depth in an image by presenting two offset images separately to the left and right eye of the viewer.

system.net.webexception is a .NET exception is thrown when an error occurs while accessing the network through a pluggable protocol.

strtol() is the C runtime library function for converting the text representation of a number to a long integer. This SO tag also applies to strtoll(), strtoul(), and strtoull() which perform the same conversion to types "long long", "unsigned long", and "unsigned long long".

AxWMPLib.AxWindowsMediaPlayer is the base class for the Windows Media Player control

MGTwitterEngine is an Objective-C/Cocoa class which makes it easy to add Twitter integration to your own Cocoa apps.

The Sobel operator, sometimes called Sobel Filter, is used in image processing and computer vision, particularly within edge detection algorithms.

Android class : "MediaMuxer facilitates muxing elementary streams."