All thirty-two counties for 1901 are now available online on the National Archives of Ireland website.
I've been waiting awhile for this day as I have quite a few ancestors from Northern Ireland. I had previously ordered an extract from Emerald Ancestors, but it would prove to be a bit costly if I wanted to search for all the names that I have. They also couldn't guarantee that they had the extracts for everyone. So when the 1911 census went online, free, I was quite excited - even if the county I wanted was one of the last to go online.
For the 1901 census, they have released all 32 counties at once. I have done a quick check and have found my grandfather (aged 4) with his family. Will have to wait until the weekend to be able to spend more time looking more thoroughly.