When this application was started around 2008 or so we had a number of frameworks to choose from. At the time we chose spring.net. Looking back on it, that was a good choice considering most of our alternatives at the time (and since) have come and gone. Particularly Microsoft technologies that seem to come and go all the time. We're pretty happy that we chose a reliable, stable and well-maintained library such as spring.net.
I am curious what alternative you'd recommend, particularly if it's something that is production ready and has a certain future.
We're well aware of how hard it is to hire good C# developers. But in my opinion, a good C# developer isn't going to be put off by the choice of Spring.NET.
I think Spring.NET is too verbose and too big. I would rather use few well tested and idiomatic C# frameworks as an alternative to Spring.NET
E.g. IOC - You can use MEF which is part of the framework. OR my personal favorite Ninject.
Web Applications - Without a doubt ASP.NET MVC.
Aspect Oriented Programming - Postsharp
DataAccess - I do not think ORM technology is mature enough to use it for any complicated work. For simpler things, Dapper does the trick.
I believe in using best tool for a given problem instead of using one monolithic framework. I especially don't like Spring framework because it needs too much configuration in terms of XML files. I prefer configuration through code approach.
I am curious what alternative you'd recommend, particularly if it's something that is production ready and has a certain future.
We're well aware of how hard it is to hire good C# developers. But in my opinion, a good C# developer isn't going to be put off by the choice of Spring.NET.