As I am writing this, I am employed as a software engineer at XS4ALL, the oldest consumer internet provider in the Netherlands.
The main difference is that IRC is mainly aimed at group conversations. IRC has channels, which can be seen as chat rooms. These channels have a name, and anyone can join them. Anything you say on a channel, is broadcast to all people who have joined that channel. Channels persist, as long as there is at least one person in them.
It is also possible to have private conversations on IRC.
So, how does this help XS4ALL?
We have several “official” channels on our office IRC server, for example a general channel for everyone, a helpdesk channel, and a sysadmin channel. In principle, everyone is welcome on any channel, but the people from the department that “own” the channel are the ones who mainly talk. The others mainly read.
If an employee has a question that he/she has not found an answer for elsewhere, he/she can ask this on the appropriate channel. Hopefully, at least one person of that department is reading along at that moment, and can answer the question.
There are several reasons why this simple concept is very powerful.
First, asking the question in a channel instead of a private conversation makes it more likely that you will get a response quickly. You don’t have to depend on one person being active at that moment.
Second, other people will be able to read your question and the answer. They will therefore learn the answers to questions, so they won’t have to ask the same question at a later time.
Third, it is simpler and more informal than a shared email box or a ticketing system. This can lead to faster replies, which allows a customer’s problem to be solved while the customer is still on the phone, instead of the employee who asked the question having to call back the customer at a later time.
Fourth, if one person gives an answer, but a second person knows a better answer, you will also get this better answer. That is a better result than email or a ticket, because it is very rare to receive more than one answer for each inquiry done that way.
Fifth, it is easy to read back an IRC channel after a couple of hours of not reading it, assuming that you keep your IRC software connected to the IRC server. That gives additional opportunities for both learning and giving delayed or improved answers.
All in all, our IRC server contributes to a significant amount of knowledge sharing among employees. It always impresses me how easy it is to learn a few things, by simply being present on a few IRC channels and reading along.
If your company is not too big, and willing to experiment a little, I can highly recommend trying IRC, or another group-based chat protocol, to improve the sharing of knowledge, and experience fast, interactive problem solving.