I-YaCy (ebizwa ngokuthi "ya kubona") yinjini yokukhangela esasazwa simahla, eyakhelwe kwimigaqo yonxibelelwano lontanga-kuya-peer (P2P). Undoqo wayo yinkqubo yekhompyuter ebhalwe kwiJava esasazwa kwiikhompyuter ezininzi, ukusukela ngoSeptemba 2006, ebizwa ngokuba yiYaCy-peers. I-YaCy-peer nganye irhubuluza ngokuzimeleyo kwi-Intanethi, ihlalutya kunye nezalathisi ezifunyenweyo kumaphepha ewebhu, kwaye igcina iziphumo zesalathiso kwisiseko sedatha esiqhelekileyo (esibizwa ngokuba yi-index) ekwabelwana ngayo nabanye abalingane be-YaCy usebenzisa imigaqo yenethiwekhi ye-P2P. Yinjini yokukhangela yasimahla enokusetyenziswa ngumntu wonke ukwakha i-portal yokukhangela kwi-intranet yabo kunye nokunceda ukukhangela i-intanethi yoluntu ngokucacileyo.