Before creating a custom tag in CFML, you will probably want to visit the Custom Tag section of the Allaire Developer Exchange. Tags are grouped in several broad categories and are downloadable as freeware, shareware, or commercial software. You can quickly view each tag's syntax and usage information. The Gallery contains a wealth of background information on custom tags and an online discussion forum for tag topics.
Tag names with the CF_ preface are CFML custom tags; those with the CFX_ preface are ColdFusion Extensions written in C++. For more information about the CFX tags, see Chapter 18, "Building Custom CFAPI Tags".
If you don't find a tag that meets your specific needs, you want to create your own custom tags in CFML.