Falcons is a keyword-based search engine for the Semantic Web. Falcons provides keyword-based search for URIs identifying objects, concepts (classes and properties), and documents on the Semantic Web.

In Falcons Object Search, you can enter several keywords about the object you want to find, and click on the "Search Objects" button. Separate keywords with the space character, and put phrases in double quotes. Boolean queries are also supported.

In the results page, for each object, we provide its title (label or local name), URI, types, and a snippet consisting of its RDF descriptions hit by the keyword query. Each resulting object, as well as each entity in the snippet, is clickable, forwarding users to its detailed description.

You can navigate a class hierarchy to refine your search.

In Falcons Concept Search, you can enter several keywords about the class or property you want to find, and click on the "Search Concepts" button. Separate keywords with the space character, and put phrases in double quotes. Boolean queries are also supported.

In the results page, for each class/property, we provide its title (label or local name), URI, types, and a snippet consisting of its RDF descriptions hit by the keyword query. Each resulting class/property, as well as each entity in the snippet, is clickable, forwarding users to its detailed description.

You can select a vocabulary from the recommended ones to refine your search. You can also restrict your search to only classes or properties.

In Falcons Document Search, you can enter several keywords about the document you want to find, and click on the "Search Documents" button. Separate keywords with the space character, and put phrases in double quotes. Boolean queries are also supported.

In the results page, for each document, we provide its label or URL, and a snippet consisting of RDF triples in the document hit by the keyword query. Each entity in the snippet is clickable, forwarding users to its detailed description.

You can submit the URL of a Semantic Web document here or use our API. Currently, we can only process documents in the RDF/XML format. The URL will eventually be checked by our crawler. However, we cannot make any predictions about when it will be indexed.

Falcons parses RDF/XML documents using Jena, stores data in MySQL, and indexes data using Apache Lucene.

Let's start with Falcon. Falcon means Finding, Aligning and Learning ontologies, ultimately for Capturing knowledge via ONtology-driven approaches. Falcon is a series of tools and services developed for the Semantic Web by Institute of Web Science (IWS), Southeast University, China. Representative tools and services in the Falcon series include Falcon-AO, a tool for Aligning Ontologies, and this Falcons system. Falcons provides fundamental services for Searching and Surfing the Semantic Web.

Gong Cheng, Yuzhong Qu
Searching Linked Objects with Falcons: Approach, Implementation and Evaluation
International Journal on Semantic Web and Information Systems 5(3):49--70, July--September 2009

Yuzhong Qu, Gong Cheng, Honghan Wu, Weiyi Ge, Xiang Zhang
Seeking Knowledge with Falcons
In Semantic Web Challenge, 2008

Gong Cheng, Yuzhong Qu
Integrating Lightweight Reasoning into Class-Based Query Refinement for Object Search
In Proceedings of the 3rd Asian Semantic Web Conference, pages 449--463, 2008

Gong Cheng, Weiyi Ge, Yuzhong Qu
Falcons: Searching and Browsing Entities on the Semantic Web
In Proceedings of the 17th International Conference on World Wide Web, pages 1101--1102, 2008

Gong Cheng, Weiyi Ge, Honghan Wu, Yuzhong Qu
Searching Semantic Web Objects Based on Class Hierarchies
In WWW 2008 Workshop on Linked Data on the Web, 2008