yCal has been designed to run on Macs with MacOS 10.10 (Yosemite) or newer. In particular, it fully supports the newest MacOS 10.14 (Mojave) and makes use of newly introduced features such as dark mode. It's currently localized in English and German.
For those who are still using an older version of MacOS, there are archives of older versions of yCal available for download on our site as well.
Download yCal version 1.5 here. Below, the compatibility list for v1.5:
A word on OSX 10.6 (Snow Leopard): after upgrading to support 10.8 we encountered a few problems on OS X 10.6. With less and less people running 10.6 (although we know it used to be one of the most popular releases of OSX), it doesn't really make sense for us to dig into the details here. We encourage you to upgrade to the newer OSX versions; and for those who want to (or have to) stick with 10.6, you can try an older version of yCal like build number 927 or 963 (you can find the old .zip files here).
Still have a problem with yCal? Take a look at the FAQs, first.