What is difference between std.signal and events?

[Uranuz]

I have read some posts about new std.signal implementation. The 
last was this review thread: 
http://forum.dlang.org/thread/ujlhznaphepibgtpcoqz@forum.dlang.org. 
What I still can't understand what is difference between signals 
and events in languages like JavaScript, C# and Borland C++ (that 
has it's own extension to language to implement events). As far 
as I understand in C# events are based on delegates but have some 
limitations. They can only be fired from owner's method. In JS 
events at my point of view are used to notify some input events 
or DOM changes. Borland C++ uses them to notify GUI events (in 
example button click). Is module called "signals" only for not 
interfere with OS IO events or is there some difference and 
reason?