Wine is animplementationof the WindowsAPI on top of Xand Unix. Itdoes notrequireMicrosoftWindows, butcan use nativeWindows DLLs ifthey areavailable. Itprovides both adevelopmenttoolkit forporting Windowssource code toUnix as well asa programloader,allowing manyunmodifiedWindowsprograms to runon x86-basedUnixes.