Here is the Link for Salesforce documention on Toolinng API: http://www.salesforce.com/us/developer/docs/api_tooling/index.htm
Short Description: Tooling API provides SOAP and REST interfaces that allow you to build custom development tools for Force.com applications. For example, you can: Add features and functionality to your existing Force.com tools. Build dynamic modules for Force.com development into your enterprise integration tools. Build specialized development tools for a specific application or service. Tooling API exposes objects used in developer tooling that you can access through REST or SOAP, and works just like the Salesforce REST API and SOAP API.
Here is the Link for Salesforce documention on Toolinng API:
http://www.salesforce.com/us/developer/docs/api_tooling/index.htm
Short Description:
Tooling API provides SOAP and REST interfaces that allow you to build custom development tools for Force.com applications.
For example, you can:
Add features and functionality to your existing Force.com tools.
Build dynamic modules for Force.com development into your enterprise integration tools.
Build specialized development tools for a specific application or service.
Tooling API exposes objects used in developer tooling that you can access through REST or SOAP, and works just like the Salesforce REST API and SOAP API.
Thanks,
Pratik