TagMe

TagMe is a powerful tool that identifies on-the-fly meaningful substrings (called "spots") in an unstructured text and link each of them to a pertinent Wikipedia page in an efficient and effective way. You can annotate a text by issuing a query to the RESTful API documented in this page. TagMe results one of the best entity linking tool in the scientific community, with very good performance especially when annotating short texts (namely, those composed by a few dozens of terms).