YaCy (inodudzwa kuti "ya kuona") injini yekutsvaga yakagoverwa yemahara, yakavakirwa pamisimboti yepeer-to-peer (P2P) network. Mhedzisiro yaro ipurogiramu yekombuta yakanyorwa muJava yakagoverwa pamakomputa mazana akati wandei, kubva munaGunyana 2006, inonzi YaCy-peers. YeCy-peer yega yega inokambaira paInternet, inoongorora uye indekisi yakawanikwa mapeji ewebhu, uye zvitoro zve indexing zvinobuda mudhatabhesi rakafanana (rinonzi index) iro rinogovaniswa nevamwe YaCy-vezera vachishandisa misimboti yeP2P network. Injini yekutsvaga yemahara iyo munhu wese anogona kushandisa kuvaka portal yekutsvaga intranet yavo uye kubatsira kutsvaga internet yeruzhinji zvakajeka.