the program (then version 1.19) won the 2002 apple design award of "best mac open source port" for its capability to display scientific and technical documents created in tex format. in fact, texshop makes it possible, thanks first to "pdfsync.sty", to switch back and forth between code and preview easily, jumping at a corresponding spot, simply by a cmd-click. from texshop 1.35 onward this also works with multipart documents, which are joined by "\include".