Google has created a specialised search engine designed to find software source code publicly available on the web.

The code search engine, which will debut today, is intended to help professional programmers, hobbyist developers and code enthusiasts with the difficult task of finding source code online, a Google official said.

Currently, the general web search engine at can find links to files with source code, but it doesn't index the actual lines of code in those files, said Tom Stocky, a Google product manager. In those cases, developers need to download the files to their computers and inspect the code.

However, the new search engine has been architected to crawl more deeply and return results containing actual snippets of code, which should make the finding process simpler, Stocky said. "We find the lines that match your query," he said.

The search results link to the full file containing the highlighted code, as well as to the software license governing the use of the code, which in most cases will be open source, he said. Developers can enter keywords or fuller patterns in the search box.

Google also plans to release an application programming interface for the search engine, so external developers can tap into it. For now, the company doesn't plan to display ads along with search results, he said.

The decision to build this code search engine stems from Google's desire to help external developers, who it considers essential to the process of improving its online services, like its maps search, and extending their popularity, he said.