This is a pretty open question. A lot of 'bar code' tasks would have little to no barring on ColdFusion and its processes.
What are you thinking your application needs to do?
Read bar codes? That is a client side issue, once the code is read it is just going to be alpha numeric data.
Display bar codes? This is just images and|or fonts and there are many available.
Store bar codes? The actual bar codes or just the data that is encoded in the bars?
I've long been aware of the Bar Code Zone product, though I have never had need to actually investigate or use it.
While google searching for that url I also saw this link to a free ColdFusion bar code utilitiy.