YaCy is free software which means that we use a free software licence, the GPL (version 2). This software was developed by a volunteer developer community, not a company; some people are listed on the right column. The source code is hosted at
We need more help from developers and other creative people!
Until now more than 30 people helped to create YaCy. Please discover our Search API and other Interfaces to YaCy to build your own applications with YaCy. Your help to extend YaCy is welcome, please clone our Git repository.
Firefox Extension: YaCyBar
Graphic and Web Designer
We don't have any designer in our team, You can help! The YaCy application and this website could use the help of a graphic designer. Please draw icons; enhance the css files, show us how to display things in a proper way.
Authors for help-texts and descriptions in the Wiki
The YaCy documentation can always use improvement, since development is fast, the content in the wiki becomes quickly out-dated. If you can't write programs but you want to help document YaCy, wiki contributions would be much appreciated.
Translation of the YaCy administration pages
The online interface of YaCy can be localized, we currently have english and german localizations. If you speak another language then you can help by doing a localization for your own language. This is not difficult and only requires translation of a localization file from german or english into the new language.
Since YaCy 1.0 we have an option to use Solr as a kind of side-kick to YaCy. A simple option provides a link to your solr installation using solr and all YaCy index data is pushed into that solr index. We wonder if Solr users may want to look at YaCy as a possible replacement of their crawler. Its very easy: have a look at the federated index page and you have attached a Solr server with some clicks. The future development of YaCy: Solr may become a standard component of YaCy.
Developers: your idea to extend the functionality of YaCy
We need more developers and your help is welcome. If you have an idea for a new function, please let us know.
We need more supporters!
Run a public peer to increase the shared web index!
To run a public peer, you need to download the YaCy installation for your operating system from the project home page. Be sure you install YaCy to a disk that has a reasonable amount of free space. After installing, remember to configure your operating system to start YaCy when your computer starts up. Finally, you'll need to make sure port 8090 is open by configuring your router or firewall (if you don't know how to do that, you'll need to search online for instructions specific to your operating system and router). After configuring your firewall/router (and with YaCy running), use an online tool such as this to verify your port is indeed open. That's it! YaCy will run as a low priority process (which means it won't stop you using your computer for the things you normally use if for). To search, open the url http://localhost:8090 with your web browser. Remember, YaCy is still growing, so search results won't be as extensive as the likes of Google just yet - but you're helping to change that!
Tell people about YaCy!
We want freedom of information. You can help by replication of that message: we need many to be able to provide a good (search) service for many. So please spread the word: free search is possible, free search is here. Help us!
Use YaCy as the search engine for your own projects
Most projects use wikis, forums, and static Web pages for their project documentation. These functional areas often have their own search technology, but they can not search across all of the different areas within the project. With YaCy you can search across all of these sources. By using YaCy as your search portal, your website will benefit and YaCy will benefit too by getting better visibility as a search solution.