Celerity is a strong application for analyzing C/C++ files. It can process millions of lines of source codes. It supports standard C/C++ (and K&R style of sources as well). For each project, it shows the source files, include files, source and include files, lexon (lexical elements) indexes, includes, include-bys, all macros, macros in a translation unit, all definitions, definitions in a file, definitions in a translation unit, references (function declarations and invocations), reference-bys, diagnosis outputs, symbol searches, favorites, etc. It produces a rich and cross-referenced database about each analyzed project. Definitions and invocations could be expanded incrementally on the fly by just a single click. All these combined help the user to rapidly understand and maitain a large code base. It has a user-friendly interface with capabilities like tabs, docking, auto-hiding, floating, drag and drop, etc. It allows the user to rapidly locate each functional window and rearrange these windows in disparate layouts. It hold a versatile editor for text/hexadecimal files. File formats could be defined to specify how to handle directives, colours, styles, etc. List of all opened files and list of all history files enable the user to locate the desired file in an easy way. It hold a workspace for multiple projects with commands dealing with each project or all projects. Strong multiple-file find & replace functions enable the user to do rapid searches within the background. It has a strong differencing module which can perform file-to-file or directory-to-directory comparations in a background manner. Many commands are provided to show various aspects about the differences. Supported operating systems: Windows 2000/XP/2003/VISTA.