There are plenty of free alternatives. What can Genome offer beyond them? On principle, we do not bash rival tools and thus will not do any feature-by-features comparisons with specific other O/RMs, open source or not. However, we get asked about certain issues again and again and we therefore feel justified to include them in our FAQs.
Genome is (as mentioned in the Why Genome? section) driven by .NET. This means that it is better adapted to new developments on the .NET platform than solutions ported from other platforms (just think about LINQ adaptation).
A quick comparison of Visual Studio integration in Genome and the open source alternatives will also show advantages. Genome compiles mappings during build time. This means high performance without runtime errors and without that nasty search for errors in the mapping. In Genome, errors can be found easily when compiling: simply click on the error and Genome will position you where you need to be to fix it - just like that.
Open source ≠ free lunch
Please be aware that open source does not necessarily mean free: if you need custom features, bugfixes or anything else urgently, you cannot even be sure that you can buy the service if necessary. In many cases, you can only hope, pray or beg that somebody on the team will take mercy on you and develop what you need. Or else, you may end up paying a hefty sum for it.
Fixing or modifying the software yourself means that you can pretty much forget about future releases. You would have to branch and merge with each successive release, and would not even have the certainty that new versions will in any way support your changes.
With Genome on the other hand, the source code is available, if required and you can ask us for the features that you need. We can implement them quickly and cost-effectively.