You can make a typical CSS border dashed or dotted. For example:

.box {
   border: 1px dashed black;
   border: 3px dotted red;
}

You don’t have all that much control over how big or long the dashes or gaps are. And you certainly can’t give the dashes slants, fading, or animation! You can do those things with some trickery though.

Amit Sheen build this really neat Dashed Border Generator:

The trick is using four multiple backgrounds. The background property takes comma-separated values, so by setting four backgrounds (one along the top, right, bottom, and left) and sizing them to look like a border, it unlocks all this control.

So like:

.box {
  background-image: repeating-linear-gradient(0deg, #333333, #333333 10px, transparent 10px, transparent 20px, #333333 20px), repeating-linear-gradient(90deg, #333333, #333333 10px, transparent 10px, transparent 20px, #333333 20px), repeating-linear-gradient(180deg, #333333, #333333 10px, transparent 10px, transparent 20px, #333333 20px), repeating-linear-gradient(270deg, #333333, #333333 10px, transparent 10px, transparent 20px, #333333 20px);
  background-size: 3px 100%, 100% 3px, 3px 100% , 100% 3px;
  background-position: 0 0, 0 0, 100% 0, 0 100%;
  background-repeat: no-repeat;
}

I like gumdrops.