看到某网友对比了多个实体识别/提取API，很有参考价值，摘录如下：
实体识别API
对比的特性
- API terms
- Languages
- Number of Entities and Relevance Scores
- Semantic Links
- Additional Information
- Synonyms vs. Duplicates
结论
引述原文作者的结论：
Overall, Evri and AlchemyAPI were definitely the best and most suited for my purposes. The quality of Evri’s was the best across the small sample, although not in all instances, and it didn’t return as many entities as AlchemyAPI. Interestingly these two APIs are also the two which include semantic links and have the least restrictions and high API limits.
OpenAmplify and BeliefNetworks are the runners up. OpenCalais fared poorly in my evaluation, but I suspect it would do better when looking at all the rest that their API. Yahoo’s API unfortunately just wasn’t good enough to use when any of the other APIs are available.