.NET here means the .NET SDK has to be on the machine to build the software and the .NET runtime to run it, on Windows, Linux or macOS. Applications can also be published self-contained, with the runtime included in the output. A record carries this value when its documentation requires .NET, and the production side shows as .NET under hosting needs. ASP.NET Core and Umbraco are examples.
10 projects need .NET installed, listed alphabetically. Mostly content management systems, web frameworks and e-commerce, of 5 categories in all. 222 records do not record this field, and cannot appear here either way. Counts only projects with momentum; the full list has the rest.
A
ASP.NET CoreCross-platform, open-source framework for building web apps and services with .NET and C#.
B
- Blazor
Web UI framework for building interactive web apps with C# and Razor components, shipped as part of ASP.NET Core.
E
- Exceptionless
Error and log reporting service with a self-hostable server, a web dashboard and client libraries for .NET and JavaScript.
G
GrandNodeOpen-source e-commerce platform built on ASP.NET Core and MongoDB, with multi-store and multi-vendor support.
O
Optimizely CMSCommercial .NET content management system from Optimizely, installed from NuGet packages on Microsoft SQL Server.
P
Progress SitefinityCommercial .NET content management and digital experience platform from Progress, offered on-premises or as a cloud service.
S
ServiceStackServices framework for .NET that builds HTTP and message-based web services from typed request DTOs.
Sitecore XPCommercial content management and digital experience platform from Sitecore, sold as an on-premises product and a cloud product.
W
- WebOptimizer
ASP.NET Core middleware that bundles and minifies CSS and JavaScript files at runtime and keeps the output in memory.
X
Xperience by KenticoContent management and digital experience platform for .NET web applications, with marketing and commerce features.
What is the best web software that runs on .NET?
We can't tell from here. What suits an editor-heavy marketing site can be wrong for a static documentation site. The list is alphabetical and nobody paid for a place on it.