Tcl/Tk 8.5.17 发布了，改进记录：
* Fixed crash in Cocoa Tk after [$button destroy]. * Stop hangs in... - some [read]s of limited size. - [gets] from non-blocking binary channels. * Fix: [gets] failure to honor non-blocking setting. * Fix: failure of [chan copy] to handle blocked input channel. * Fix: Cocoa: PNG transparency appearance. * Fix: Cocoa: button and scroll display. * Fix: manage effects of [text] elide changes. * Enhancement: Cocoa: improved drawing performance. * Corrected button click event handling to support browser plugin. * Update: Support build and run on OS X Yosemite. * Update: MSVC14 compile support.