Table 2: NLP APIs selected for the prototype.

APIFeeCompany/teamReferences

IBM Watson NLUFree trialIBMhttps://www.ibm.com/watson/developercloud/natural-language-understanding/api/v1/
MeaningCloudFree trialMeaningCloud LLChttps://www.meaningcloud.com/developer/documentation
Open CalaisFree trialThomson Reutershttp://www.opencalais.com/opencalais-api/
Haven OnDemandFree trialHewlett Packardhttps://dev.havenondemand.com/apis
TextRazorFree trialTextRazor Ltd.https://www.textrazor.com/docs/rest
Dandelion APIFree trialSpaziodatihttps://dandelion.eu/docs/