I was asked the other day for some insight into what CMS's are .NET. I compiled a quick list and thought I'd share it:
Open Source
1. N2 – open source, very lightweight, requires a lot of development. It’s more of a framework
2. Umbraco – open source, new to the marketplace, but it looks promising - https://umbraco.com/
3. DotNetNuke – open source, very mature CMS, however it is a little challenging to use if you don’t know the tool very well. We know this tool. https://www.dnnsoftware.com/
Low Market Solutions ( < 20K)
1. Ektron – cheaper than Sitecore or Elcom, but lacks many features, can only build a single site w/ it and it doesn’t scale well
2. Kentico – as cheap as Ektron https://www.kentico.com/

3. Sitefinity – cheap also (< 5K). This is built by Telerik, they build a lot of add-in .NET controls - https://www.progress.com/sitefinity-cms

Mid Market Solutions (20 - 75K)
1. Elcom – about the same price as Sitecore, however, it doesn't appear to have as many features. This is an australian company trying to break into the US market - https://www.elcom.com.au/
2. Sitecore – this is an excellent commercial tool. Almost as good as higher priced options. We’ve used it for a number of clients – https://www.sitecore.com/

3. Episerver - this product is very good as well. It's a Swedish company trying to break into the US. Lots of flexibility and well built at it's price point to compete with higher priced options. The addition of a Module Exchange / Developer community makes this product a very good option for people looking for .NET - https://www.episerver.com/

4. Microsoft CMS or MOSS - Microsoft's offering can somewhat be considered a CMS - https://www.microsoft.com/en-us/microsoft-365/sharepoint/collaboration?ms.officeurl=sharepoint&rtc=1

I think that's about it for PURE .NET products. The enterprise ones that are partially .NET are:
Enterprise Solutions
1. Open Text Web Solutions (RedDot) - this has been partially .NET for a few releases and will be all .NET in some yet-to-be-dated release. It's partially .NET on the CMS side, but not on the delivery side - https://www.opentext.com/
2. SDL Tridion - also partially .NET on the CMS side, but not on the delivery side - https://www.sdl.com/products-and-solutions/content-management/sdl-tridion/

There isn't a great deal of options for .NET in the Enterprise space b/c most of the products in the Enterprise space were built before .NET existed.
Let me know if you come across any more!