It depends. There are a large number of dead projects. There are also a large number of libraries and tools that are active and widely depended on, but you may

It depends. There are a large number of dead projects. There are also a large number of libraries and tools that are active and widely depended on, but you may not have heard of them. Then there are quite a few large projects donated by corps with active communities. See this page https://projects.apache.org/statistics.html https://projects.apache.org/statistics.html and scroll down to "Largest/Busiest repositories". There's a list of widely used enterprise software in there which are definitely not dead.