Emulator is a software or hardware device with emulation program to imitate another program or device. A software emulator allows computer programs to run on a platform (computer architecture and/or operating system) other than the one for which they were originally written. A hardware emulator is an emulator which takes the form of a hardware device. Examples include printer emulators inside the ROM of the printer, and FPGA-based emulators.

Enterprise Software is a type of software that solves an enterprise wide problem (rather than a departmental problem) and usually enterprise software is written using Enterprise Software Architecture. Due to the cost of building what is often proprietary software only large organizations attempt to build software that models the entire business enterprise and is the core system of governing the enterprise and the core of business communications within the enterprise. Enterprise software is often categorized by the business function that it automates - such as accounting software, human resource management or sales force automation software. It also varies by industry verticals due to common business processes within a specific industry. There are enterprise systems devised for health care, for example, or for manufacturing enterprises.

Enterprise Software Architecture, also known as Enterprise Architecture, is the practice of applying a comprehensive and rigorous method for describing a current and/or future structure and behaviour for an organization's processes, information systems, personnel and organizational sub-units, so that they align with the organization's core goals and strategic direction. Although often associated strictly with information technology, it relates more broadly to the practice of business optimization in that it addresses business architecture, performance management and process architecture as well.

Entropy, a concept in physics, is a measrue of disorder or randomness of a system. In data compression, it is a measure of the amount of non-redundant and non-compressible data in an object (the amount that is not similar). In encryption, it is the amount of disorder or randomness that is added. In software, it is the disorder and jumble of its logic, which occurs after the program has been modified over and over.

Extended Static Checker for Java (ESC/Java) is a Compaq (now part of HP) programming tool that attempts to find common run-time errors in Java programs by static analysis of the program text. Users can control the amount and kinds of checking by annotating their programs with specially formatted comments or pragmas.

Etnus TotalView is a debugger for Unix-like and Mac OS X systems and supports C/C++ and Fortran. It allows process control down to the single thread, the ability to look at data for a single thread or all threads at the same time, and the ability to synchronize threads through breakpoints. TotalView integrates memory leak detection and other heap memory debugging features. Data analysis features help find anomalies and problems in the target program's data, and the combination of visualization and evaluation points let the user watch data change as the program executes.

An evaluation strategy (or reduction strategy) for a programming language is a set of (usually deterministic) rules for defining the evaluation of expressions under β-reduction. Emphasis is typically placed on functions or operators — an evaluation strategy defines when and in what order the arguments to a function are evaluated, when they are substituted into the function, and what form that substitution takes. A language may combine several evaluation strategies; for example, C++ combines call-by-value with call-by-reference. Most languages that are predominantly strict use some form of non-strict evaluation for boolean expressions and if-statements.

Exec Shield is a security patch for the Linux kernel that adds an NX bit to x86 CPUs. It was developed by Ingo Molnar of Red Hat, and is used as a part of Fedora Core 1, 2 and 3. Exec Shield attempts to flag data memory as non-executable and program memory as non-writeable. This suppresses many security exploits, such as those stemming from buffer overflows and other techniques relying on overwriting data and inserting code into those structures. Exec Shield also supplies some address space layout randomization for the mmap() and heap base.

Extended ASCII, also known as high ASCII, is a set of codes using 8 bits for each character, instead of 7 bits as the basic ASCII set. The basic ASCII set provides it a total of 128 unique symbols. The extended ASCII character set gives it an additional 128 characters. The extra characters represent characters from foreign languages and special symbols for drawing pictures.

Extensible Markup Language (XML), a subset of SGML, defines a syntax that lets you create markup languages to specify information structures. Information structures define the type of information, for example, subscriber name or address, not how the information looks (bold, italic, and so on). External processes can manipulate these information structures and publish them in a variety of formats. Text markup language designed to enable the use of SGML on the World Wide Web. XML allows you to define your own customized markup language. XML tags are not predefined. You must define your own tags. XML uses a Document Type Definition (DTD) or an XML Schema to describe the data. XML is not a replacement for HTML. Actually, XML and HTML are complimentary to each other.