History:- A programming tool or software tool is a program or application that software developers use to create, debug, maintain, or otherwise support other programs and applications. The history of software tools began with the first computers in the early 1950s that used linkers, loaders, and control programs. Tools became famous with UNIX in the early 1970s with tools like grep, awk and make that were meant to be combined flexibly with pipes. Tools were originally simple and light weight. As some tools have been maintained, they have been integrated into more powerful integrated development environments (IDEs). These environments consolidate functionality into one place, sometimes increasing simplicity and productivity, other times sacrificing flexibility and extensibility. The distinction between tools and applications is gloomy. For example, developers use simple databases (such as a file containing a list of important values) all the time as tools. However a full-featured database is usually thought of as an application in its own right. For many years, computer-assisted software engineering (CASE) tools were sought after. Successful tools have proven elusive. In one sense, CASE tools emphasized design and architecture support, such as for UML. But the most successful of these tools are IDEs.