Google is constantly improving their search engine. Google Panda is one of those. Panda search results ranking algorithm was first released in February 2011. The change aimed to lower the rank of low-quality sites and return better and higher-quality sites at the top of the search results.
This sites traffic has been very low since. I used to have 400 organic visitors per day and it dropped to just a few. For a long time I did nothing and thought that the knowledge of this site has expired. Which wasn't true.
Lately I have started to think about this. First I did my research to see that the drops in my traffic have been at the Panda releasing dates. Which was more or less true.
I have made small SEO improvements that haven't helped me much. I compressed my js and css. I have made use of the structured data functionality of webmasters tools.
Today I have taken a big step and deleted all of the links, only content written by me is left. In a matter of fact the site has became my own resources collection and blog type website than what it was originally planned (a tutorials directory).