lastRSS.php is simple yet powerfull PHP class to parse RSS 0.9x, 1.0 and 2.0. It use quick regullar expressions instead of XML parser and returns associative array with RSS fields as a result.

USPExpress Math Parser is a component that is aimed to parse and evaluate scientific, engineering and math expressions on-the-fly. There are .NET and COM editions of USPExpress available.

USPExpress has been widely used in numerous enterprise-level applications in the field of chemical engineering and statistical applications for over 3 years now.

Parser Generator is a YACC and Lex programming tool for Windows. It is able to generate C, C++ and Java parsers and lexical analysers. This includes both Unicode and Multibyte Character Set (MBCS) variants. In your applications you can create multiple, thread safe, instances of these parsers and lexical analysers. Direct support is provided with Parser Generator for Visual C++ and Borland C++ and C++Builder.

Metaspec C# parser library is designed to provide the kernel for applications which require processing C# source code: refactoring, formatting, and verification applications, and other similar tools. C# parser is fully compliant with ECMA-334 and ECMA-335 standards. In addition, it supports Microsoft-specific extensions.
C# parser is available in two versions: a compilation parser and a transformation parser.

Janino is a compiler that reads a Java expression, block, or source file, and generates Java bytecode that is loaded and executed directly. It is not intended to be a development tool, but an embedded compiler for run-time compilation purposes, such as expression evaluators or "server pages" engines like JSP.

CalculatorX is an enhanced expression calculator. It can evaluate an expression for one time. You can use Arithmetic, Logic, Bitwise and Relation operations in your expression. And many system constants and built-in functions can also be used in the expression. CalculatorX even supports the custom variables, custom functions and note-line. You can use Binary, Octal, Decimal and HEXadecimal numbers in one expression to evaluate as well.

A super-fast, low-memory usage, XML parser specifically designed to be used server-side in ASP scripts. This DOM based parser is many times faster than MSXML, and consumes far less memory. Great for handling large XML data files. Also includes international character codeset conversion capability.

Popular XML parser for C#, VB.NET, and ASP.NET

#Calculation component is a powerful calculation engine for your applications. This ActiveX component integrates expression parsing and evaluation. It is suitable for heavy-duty number crunching. It also allows defining variables and sets of related formulas that implement spreadsheet-like recalculations. Even it can support matrix, array, note-line and custom-functions in your expression.

#Calculation component is a powerful calculation engine for your applications. This ActiveX component integrates expression parsing and evaluation. It is suitable for heavy-duty number crunching. It also allows defining variables and sets of related formulas that implement spreadsheet-like recalculations. Even it can support matrix, array, note-line and custom-functions in your expression.

JEP is a Java library for parsing and evaluating mathematical expressions. With this package you can allow your users to enter an arbitrary formula as a string, and instantly evaluate it. JEP supports user defined variables, constants, and functions. A number of common mathematical functions and constants are included.