..to help improving other documentations as well :)

This is a nice format but losing RSS Feed notifications is a drawback.

Add a link to reference source code to easily view source of current class/method

Performance is very poor. E.g. for a page picked at random you are in the bottom 50% of sites in terms of speed according the pingdom speed test. See e.g. https://tools.pingdom.com/#!/dYpCmZ/https://docs.microsoft.com/en-us/uwp/api/windows.ui.input.spatial.spatialp

You take 48 requests (including 21 scripts!) and 1.22MB to show some a site where the valuable content is text.. Speed is critical for technical docs, since you tend to click around so much.

While the offline viewing option is great, PDF's "baked in" page format makes reading on mobile devices very cumbersome. I suggest offering downloads in open ePub format for easy reading on mobile devices -- allowing for text reflow, text and margin adjustment, color themes, etc.

On the documentation organization\navigation topic, one way of doing the documentation that is used for some product in Azure is the learning map\path (example: https://azure.microsoft.com/en-us/documentation/learning-pat...). I just LOVE that approach, it's visual, it's clear, you know where you are and where you are going, it's task oriented: it's perfect.

Support searching for parts of API names - e.g. index camel cased word parts.

Currently, there are no Results for "NullOrEmpty" - which is just a full part of "IsNullOrEmpty".

It would also be helpful to fuzzily match up names (better than no results): e.g. "isnowhi" should include "String.IsNullOrWhitespace" in the results (ranked below a possible "IsNowhereIncluded" method).

It would be great to be able to see the first/minimum version that a namespace is introduced. This way, if you are browsing and realize that you really only need .Net Standard 1.3 instead of 1.6, for example, you can see that quickly without having to flip back and forth. Alternatively, having a feature comparison chart where 2+ .Net versions are selected and their namespaces are compared would serve the same purpose.

Would love an API for programmatically searching for content.

For example, in the existing MSDN documentation for IEnumerable<T>, we also see all of the extension methods that are defined for that type:

https://msdn.microsoft.com/en-us/library/9eekhta0(v=vs.110).aspx

In the new .NET API Browser, the IEnumerable<T> reference only lists the GetEnumerator() method. None of the documentation for IEnumerable<T> says anything about the presence of these extension methods or even links to System.Linq.Enumerable.

https://docs.microsoft.com/en-us/dotnet/api/System.Collections.Generic.IEnumerable-1

There is no obvious location for it when you arrive on the home page. Neither the .NET Core nor ASP.NET Core pages have links to it that I found. Maybe there is a link three or four levels deep, but it is ridiculous to make someone click around that much to find it.

The date in article headers is great, but can it please be localised (e.g. dd/mm/yyyy in the UK) rather than assuming US-format dates?

Please make the (left) navigation pane a little wider on wide screen monitors (1600px). It will increase readability in both the navigation pane (particularly in case of indented content) and main content.

Add support for ASP.NET Core Api reference
Also Identity Core and EF Core

Based on keywords, expose articles in either xml or json so third party apps can integrate documentation.

The native scrollbar may be light and high contrast with the background. It's quite disturbing.

Right now Monitor.​Wait is displayed as:

Monitor.​Wait(​System.​Object,​System.​Int32,​System.​Boolean)

Much easier to read version would be:
Monitor.​Wait(object, int, bool)

From a developer point of view, when searching some information over a software topic, it is, typically, over a specific version. MSDN result search point to the most recent version of that software which could lead to misinformation, e.g. deprecated functionalities or even new functionalities not currently supported. With a user preference about a specific software, it could lead to a more accurate and faster search result.

Every member has a collapse button, but member groups don't have a Collapse All.