IronSoftware

Posted on Jan 2

Why Choose .NET for Cross-Platform Development?

#csharp #dotnet

.NET runs on Windows, macOS, Linux, iOS, Android, and the web. One codebase. Multiple platforms. Here's why that matters.

// Same code runs everywhere
var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.MapGet("/", () => "Hello from any platform!");

app.Run();

Build on your Mac. Deploy to Linux. Develop on Windows. Target mobile. One language. One framework.

Wasn't .NET Windows-Only?

That was .NET Framework. Dead since 2019.

Modern .NET (formerly ".NET Core") is fully cross-platform since version 1.0 in 2016. Microsoft rewrote the runtime for portability. Today:

.NET 10 runs natively on Windows, macOS, and Linux
Apple Silicon (M1/M2/M3/M4) has first-class support
ARM processors are fully supported
Containers work on any Linux distribution

The old Windows-only days are over.

What Platforms Can I Target?

Server/Desktop

Platform	Support Level
Windows x64	Full support
Windows ARM64	Full support
macOS x64 (Intel)	Full support
macOS ARM64 (Apple Silicon)	Full support
Linux x64	Full support
Linux ARM64	Full support
Alpine Linux	Full support

Mobile

Platform	Technology
iOS	.NET MAUI
Android	.NET MAUI
iPadOS	.NET MAUI

Web

Target	Technology
Server-side web	ASP.NET Core
Client-side web	Blazor WebAssembly

Desktop

Platform	Options
Windows	WPF, WinForms, MAUI, Avalonia
macOS	MAUI, Avalonia
Linux	Avalonia

How Does Cross-Platform Work?

.NET compiles to Intermediate Language (IL). At runtime, the Just-In-Time (JIT) compiler translates IL to native machine code for the current platform.

C# Code → IL (platform-independent) → Native Code (platform-specific)

You write once. The runtime handles platform differences.

Can I Cross-Compile?

Yes. Build for any platform from any platform:

# Build Windows executable on macOS
dotnet publish -r win-x64 --self-contained

# Build Linux binary on Windows
dotnet publish -r linux-x64 --self-contained

# Build macOS app on Linux
dotnet publish -r osx-arm64 --self-contained

Self-contained deployment bundles the .NET runtime. Your app runs on target machines without .NET installed.

What About Performance?

.NET performance is excellent on all platforms. The JIT compiler optimizes for each CPU architecture.

TechEmpower benchmarks consistently show ASP.NET Core among the fastest web frameworks. The same performance advantage applies to:

Linux servers (most production deployments)
macOS development machines
Windows desktop applications

No platform penalty.

What Is .NET MAUI?

Multi-platform App UI. Build mobile and desktop apps from one codebase:

// Shared UI code
public class MainPage : ContentPage
{
    public MainPage()
    {
        Content = new StackLayout
        {
            Children =
            {
                new Label { Text = "Hello, World!" },
                new Button { Text = "Click Me" }
            }
        };
    }
}

This runs on:

iOS
Android
macOS
Windows

One project. Four platforms.

What Is Blazor?

Web UI framework using C# instead of JavaScript:

Blazor Server: UI runs on server, updates via SignalR
Blazor WebAssembly: UI runs in browser via WebAssembly

@page "/counter"

<h1>Counter: @count</h1>
<button @onclick="Increment">Click me</button>

@code {
    private int count = 0;
    private void Increment() => count++;
}

C# developers building web apps without learning JavaScript frameworks.

What Is Avalonia?

Open-source cross-platform UI framework. Unlike MAUI, it supports Linux desktop:

// Runs on Windows, macOS, AND Linux
public class MainWindow : Window
{
    public MainWindow()
    {
        Content = new TextBlock { Text = "Hello, Linux!" };
    }
}

True desktop application support on all three major operating systems.

What About Containers?

.NET is container-native:

FROM mcr.microsoft.com/dotnet/sdk:10.0 AS build
WORKDIR /app
COPY . .
RUN dotnet publish -c Release -o out

FROM mcr.microsoft.com/dotnet/aspnet:10.0
WORKDIR /app
COPY --from=build /app/out .
ENTRYPOINT ["dotnet", "MyApp.dll"]

Microsoft provides official images:

sdk — Building apps
aspnet — Running web apps
runtime — Running console apps

Alpine variants for minimal image size (~100MB for web apps).

How Do Teams Benefit?

Mixed Development Environments

Developer A: Windows + Visual Studio
Developer B: macOS + Rider
Developer C: Linux + VS Code

Same codebase. Same build. Different machines.

CI/CD Flexibility

Build on any platform:

GitHub Actions (Ubuntu runners are cheapest)
Azure DevOps (Linux, Windows, macOS)
Jenkins (any platform)

Deployment Options

Linux containers (most cost-effective)
Windows Server (enterprise environments)
Azure App Service (managed PaaS)
AWS Lambda (serverless)
Any cloud, any platform

What Are the Alternatives?

Framework	Pros	Cons
Java	Mature ecosystem	Verbose, slower evolution
Python	Easy to learn	Slower runtime, GIL
Go	Simple, fast	Less mature ecosystem
Node.js	JavaScript everywhere	Single-threaded, callback complexity
Rust	Memory safe, fast	Steep learning curve

.NET offers:

Modern language features (C# evolves yearly)
Strong performance
Excellent tooling
Large ecosystem
Enterprise support

What About Vendor Lock-In?

.NET is open source. The runtime, libraries, and SDK are all on GitHub under MIT license.

You can:

Fork the code
Build from source
Run anywhere

Microsoft maintains it, but you're not locked in.

When Should I NOT Use .NET Cross-Platform?

iOS/Android games: Unity (uses C# but separate runtime)

Low-level systems programming: Rust or C++

Quick scripts: Python might be faster to write

Maximum ecosystem size: JavaScript/Node.js for web

For most business applications, .NET cross-platform is an excellent choice.

Quick Setup for Cross-Platform

# Install .NET SDK
# Windows: winget install Microsoft.DotNet.SDK.10
# macOS:   brew install dotnet-sdk
# Linux:   sudo apt install dotnet-sdk-10.0

# Create cross-platform web app
dotnet new webapi -n MyApi
cd MyApi
dotnet run

# Build for different platforms
dotnet publish -r linux-x64 --self-contained
dotnet publish -r osx-arm64 --self-contained
dotnet publish -r win-x64 --self-contained

Summary

Question	Answer
Does .NET run on Mac?	Yes, natively
Does .NET run on Linux?	Yes, natively
Can I build mobile apps?	Yes, with MAUI
Can I build web apps?	Yes, with ASP.NET Core and Blazor
Is it open source?	Yes, MIT license
Is there vendor lock-in?	No
Is performance good?	Among the fastest

.NET in 2025 is a true cross-platform framework. Windows-only is history.

Written by Jacob Mellor, CTO at Iron Software. Jacob created IronPDF and leads a team of 50+ engineers building .NET document processing libraries.

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