If you are a new or an experienced programmer, looking and understanding the source code of others will always help you out in many situations. Source Code search engines help you a lot when you are looking for some specific code. Here I am going to list my 5 favorite source code search engines.

1) Google Code Search

When it comes to search engines, the first name that comes to your mind is Google and they do have a search engine for source codes. You can search public repositories like GitHub and Sourceforge, Google Code from it. You can even look for a particular class or package. It also supports a lot of languages.

2) Koders

Koders is another popular choice when it comes to source codes. It searches over 1 billion lines of code in a variety of languages like C,C++, Java, ASP, Ruby, C# etc. It also displays the project matches which are related to your search.

3) Krugle

Krugle is one of the largest source code search engines. It searches over 2.5 billion lines of code. You can perform search based on language, functions, projects etc.

4) Codase

Codase is another choice when it comes to source code search engines. It is a lot behind the above mentioned top 3 as it only searches 250 million lines of code and supports only C, C++ and Java.

5) Code Fetch

Code Fetch is a good choice when you are looking for source code examples which are given in programming books. This is a good choice for people who are learning programming.

If you know any more, do mention them in comments, I will update the list.