I believe 51.ca is based on open source system, because its layout and some features are too similar as the famous open source system — DeDeCMS.

I have found some evidences, today I found one more, and this time I decided to copy the screen and I want to record it to my blog.

See here: http://info.51.ca/community/event/goodplace/ (at least 2008 June 21 is available to see the evidence)

And See the picture in the following:

(我一直相信51.ca是用开源程序做的，因为无论是其外观还是特性，都和DeDeCMS很相像。后来我发现了很多证据确实是来自DeDeCMS，今天我又发现一个，于是我决定把其屏幕拷贝下来，记在我的博客中，娱乐一下，呵呵。

看这里可以看到: http://info.51.ca/community/event/goodplace/ (至少在2008 June 21 是可以看到这个画面的)

另外可以看下图)