Human Language Technology (HLT) allows machines to understand human language through technologies like speech recognition, natural language processing, and text analysis. HLT is being used for applications that search recorded audio and video archives to enable disclosure and reuse of historical collections. Examples discussed include searching radio interview collections from the Netherlands, oral histories from the Buchenwald concentration camp, and parliamentary transcripts. HLT can recognize speech and associate it with synchronized presentation slides to enable keyword search of lecture recordings.