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Blazor client-side and WCF

I'm trying to use client-side Blazor to display some data, provided by existing WCF service. I was able to add a connected service reference, the proxy is generated. But when I'm trying to invoke it like this:
var client = new SoftConServiceClient();
await client.PingAsync(new PingRequest());
there is a bunch of errors, related to MonoTouch. By digging into the code of Mono, there is an explicit NotImplementedException in the constructor of the System.ServiceModel.DnsEndpointIdentity.
Am I right to assume that there is no way now to call legacy WCF service from Blazor client-side? If that's not the case, can anyone share a guide about how to properly do it?
Bonus question: if that is not possible, what would be the best option to approach this? Modify WCF to become REST-ish or just drop it and implement .net core api service?
Thanks a lot in advance!

Core does not support WCF very well instead of not at all. Especially in terms of authentication and security, such as the service created by using WS* binding. But for services created by using BasicHttpBinding or Restful styles services. We could invoke them normally on Core-based clients, whether using client proxy class or Channel Factory.
Please refer to below official repository.
https://github.com/dotnet/wcf
I suggest you re-construct your server project with BasicHttpBinding or using Asp.net WebAPI to create the backend service.
https://learn.microsoft.com/en-us/aspnet/web-api/overview/getting-started-with-aspnet-web-api/tutorial-your-first-web-api
Feel free to let me know if there is anything I can help with.

WCF is not supported in .NET Core out of the box, however there seems like there is a community project that is working on adding support for it in .NET Core
https://github.com/CoreWCF/CoreWCF
See What replaces WCF in .Net Core? for more info.

Am I right to assume that there is no way now to call legacy WCF
service from Blazor client-side?
Yes, you're right... WCF is not supported in Blazor client-side, and it won't be supported in the future. Microsoft has decided to stop supporting it as from .Net 5.0, and suggest to use Web Api instead.
Depending on how much you are invested in WCF, you may shift to Web API, perhaps gRPC, or go on using WCF, hoping that the efforts of the community to port and support WCF might succeed.

I was able to to put WCF 4.7.2 using techniques found with SoftCore in .Net 5.
I can also work SoftCore Hosted Example Blazor Server.

Consuming IIS-hosted WCF Service from Linux Web Application

I was tasked at work to create a web application (viewable in Firefox on Linux!) that displays results in a tabular format using data exposed by a WCF service (written in C#) hosted on a separate Windows 7 machine on the same network. Rather than returning formatted HTML, the WCF service returns structs and it will be up to the client application to take these objects, pull out the data, and format it.
Unfortunately, it has been a couple years since I have worked with any sort of web technologies. What is the best approach to solve this problem? Is there anything more current than REST/AJAX/JSON/jQuery technologies? If anyone can point out some helpful and current resources on the proper way to accomplish this, it would be most appreciated.

Use a SOAP framework to consume the WCF service. Configure WCF to use SOAP (one of the HTTP-bindings).
Webservices are easy to consume these days thanks to a standard RPC format (SOAP) and libraries supporting it. You can surely find a SOAP client for any language you are proficient in.

Checking back in here to report my own solution for this problem. I ended up going a bit of a different route that produced the simplest solution for the situation. Instead of consuming any services on the Linux side, I simply made an ASP.NET website on the Windows/IIS side (where it is easy to consume the WCF services right from Visual Studio), and then just render the website on the Linux side via the URL in a Firefox browser. For me, that fulfilled the customer requirements and was perfect, although this may not be the best approach for others that need to work with or manipulate the data in some way.

Is there such a thing as an entirely empty website project?

I'm looking at working my long-standing API to run on IIS rather than in a desktop app as it is now. Everything on the API is working so I'd rather not change too much if I don't have to. I know about the new Web API template in ASP.NET MVC 4 and I've worked with it, but I found that it didn't give me the control over everything that this particular project needs.
So my question is, is there any way to build an application for IIS that has something like an entry-point where I can just get a web request then use entirely my own code from there? Or do I have to build something that uses the Web API?

Yes, you'll want an ASP.NET handler.
How To Create an ASP.NET HTTP Handler by Using Visual C# .NET
http://support.microsoft.com/kb/308001
You'll need to handle parsing the request and serializing the result yourself. It's probably much better to create a web-api facade in front of your services than trying to do it manually.

best method to refer .Net functions via php

can any one please advice me, is there any possibilities to access .Net modules using php

One thing that i can suggest is
step 1 : create web service in .net which is client script enable
or create one aspx page
setp 2 : call the web service method or web page using jquery ajax or javascript ajax
by this way you can achieve things you want

Ditto pranay. .NET makes it extremely easy to create WSDL-based web services that PHP can easily communicate with. In my experience you should shy away from using DLLs if you can - doing so locks you into running your application on IIS, bit of a nasty surprise and rewrite if you ever need to switch your PHP application to a *nix based server setup.
However, depending on your needs you may not want/need to call it using jQuery. PHP has more than adequate SOAP functionality built into the core.

How do I return a standard name=value while using c# web service

I am creating a few basic web services using c#, and I am trying to have the web service return back just a normal name=value&name=value without any kind of xml or json format. The legacy system hitting these services is fairly old and doesn't support xml or json. Is doing this possible?

If the legacy service that's targeting this web service is that old, how exactly are you calling the web service from it? It may be easier to create an .aspx page (or even better, .ashx) that parses the request and makes the response simply using Response.Write.
If you update your question/add a comment with the detail about how you're calling the service, I'll update my answer accordingly =)