The 2024 Guide to Silverlight React Migration Platforms for Financial Services

Microsoft officially ended support for Silverlight in October 2021, yet thousands of mission-critical financial applications—from risk management dashboards to high-frequency trading terminals—still linger in a state of "technical purgatory." For financial institutions, the transition isn't just about moving from one framework to another; it is about preserving complex business logic, maintaining pixel-perfect UI fidelity, and ensuring regulatory compliance.

Choosing the right silverlight react migration platforms is the difference between a seamless digital transformation and a multi-year project failure that hemorrhages capital. This guide analyzes the top solutions available for converting legacy XAML-based architectures into modern, high-performance React environments.

TL;DR: Best Silverlight to React Migration Platforms#

• •Best for Visual Fidelity & Design Systems: Replay – Uses visual reverse engineering to convert recordings into documented React code.
• •Best for C# Logic Preservation: OpenSilver – Replaces the Silverlight runtime while keeping C# codebases intact.
• •Best for Enterprise Automation: Mobilize.Net – A heavy-duty transpilation engine for large-scale code conversion.
• •Best for Web-Enabling Desktop Apps: Wisej – Focuses on moving Windows-based logic to the browser with a React-friendly output.

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The Financial Services Dilemma: Why Silverlight Migration is Non-Negotiable#

Financial services operate on precision. In the mid-2000s, Silverlight was the gold standard for FinTech because it offered robust data binding, complex data grids, and high-performance charting that HTML4 simply couldn't touch. Today, those same applications are security liabilities.

When evaluating silverlight react migration platforms, financial IT leaders face three primary challenges:

1. •Lost Documentation: The original developers of the Silverlight app are often long gone, leaving behind "black box" logic.
2. •High-Density UIs: Trading screens often contain hundreds of data points that must update in real-time without lagging.
3. •Regulatory Compliance: Every UI change must be audited to ensure that data visualization remains accurate to the underlying ledger.

React has emerged as the definitive successor due to its massive ecosystem, virtual DOM performance, and the availability of high-end component libraries like AG Grid, which mirror the functionality of legacy Silverlight controls.

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Top 7 Silverlight React Migration Platforms#

1. Replay (The Visual Reverse Engineering Leader)#

Replay represents a paradigm shift in how migrations are handled. Instead of attempting to "transpile" brittle, 15-year-old C# code into messy JavaScript, Replay uses a visual-first approach.

By recording a session of the legacy Silverlight application, Replay’s AI-powered engine analyzes the UI patterns, layout structures, and data flows. It then generates clean, documented React components and a structured Design System. For financial services, this is invaluable because it captures the intent of the UI, even if the underlying Silverlight source code is undocumented or messy.

• •Pros: Generates human-readable React/TypeScript; creates a reusable Design System; requires no access to original C# source code for UI reconstruction.
• •Cons: Focuses on the frontend; complex backend business logic still requires manual porting to Node.js or .NET Core.

2. OpenSilver#

OpenSilver is an open-source reimplementation of Silverlight that runs on WebAssembly (Wasm). It is not a "migration to React" in the traditional sense, but rather a way to run Silverlight code in a modern browser. However, many firms use it as a stepping stone, gradually replacing OpenSilver components with React components over time.

• •Pros: Highest level of code reuse; supports C# and XAML directly.
• •Cons: Performance overhead of WebAssembly; doesn't provide a native React experience; difficult to find talent for long-term maintenance.

3. Mobilize.Net (Visual Basic Upgrade Companion)#

Mobilize.Net is a veteran in the migration space. Their toolset uses static code analysis to transform Silverlight projects into Angular or React. It attempts to map Silverlight controls to their closest modern equivalents.

• •Pros: Highly automated; handles large volumes of code.
• •Cons: The resulting code often feels "machine-generated" and can be difficult for React developers to maintain without significant refactoring.

4. Wisej.NET#

Wisej.NET provides a platform for migrating complex desktop and Silverlight applications to the web. It offers a set of controls that look and behave like enterprise desktop components but are built for the modern web.

• •Pros: Excellent for "thick client" style applications; strong support for complex data grids.
• •Cons: Proprietary framework dependencies; moving away from Wisej later can be difficult.

5. Uno Platform#

Uno Platform allows for C# and XAML code to run on the web via WebAssembly, as well as on mobile and desktop. Like OpenSilver, it is a bridge. It is increasingly being used by financial firms that want to maintain a single C# codebase while slowly introducing React micro-frontends.

• •Pros: Multi-platform support; active community.
• •Cons: High learning curve; XAML-based web development is a niche skill compared to React.

6. CSHTML5 (C#/XAML for HTML5)#

The precursor to OpenSilver, CSHTML5 is still used for legacy migrations. It converts C# and XAML into HTML and JavaScript. While it has been largely superseded by Wasm-based tools, it remains a viable option for simpler Silverlight apps that don't require the full power of WebAssembly.

• •Pros: Lightweight compared to Wasm solutions.
• •Cons: Limited support for modern React patterns; aging codebase.

7. BluePhoenix#

BluePhoenix specializes in automated modernization of legacy systems. They provide custom-tailored migration paths for Silverlight to React, often involving a mix of automated conversion and manual cleanup.

• •Pros: Custom-tailored approach; handles complex backend integrations.
• •Cons: Higher cost; longer lead times for custom engine configuration.

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Comparing the Top Silverlight React Migration Platforms#

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Technical Deep Dive: From XAML to React Components#

When using silverlight react migration platforms, the most significant technical hurdle is the shift from the MVVM (Model-View-ViewModel) pattern in XAML to the functional component and hook-based architecture of modern React.

The Legacy: Silverlight XAML#

In Silverlight, a data grid for a portfolio view might look like this:

xml
<!-- Legacy Silverlight XAML -->
<sdk:DataGrid x:Name="PortfolioGrid" AutoGenerateColumns="False" ItemsSource="{Binding Portfolios}">
    <sdk:DataGrid.Columns>
        <sdk:DataGridTextColumn Header="Ticker" Binding="{Binding Ticker}" />
        <sdk:DataGridTextColumn Header="Price" Binding="{Binding Price, StringFormat=\{0:C\}}" />
        <sdk:DataGridTextColumn Header="Change" Binding="{Binding Change}" />
    </sdk:DataGrid.Columns>
</sdk:DataGrid>

The Modern Destination: React + TypeScript#

A platform like Replay would analyze that grid and generate a high-performance React component, likely utilizing a library like Tailwind CSS for styling and a robust data table logic.

typescript
// Modern React Component generated via Replay logic
import React, { useMemo } from 'react';
import { useTable } from 'react-table';

interface PortfolioItem {
  ticker: string;
  price: number;
  change: number;
}

export const PortfolioGrid: React.FC<{ data: PortfolioItem[] }> = ({ data }) => {
  const columns = useMemo(() => [
    { Header: 'Ticker', accessor: 'ticker' },
    { 
      Header: 'Price', 
      accessor: 'price',
      Cell: ({ value }: { value: number }) => `$${value.toFixed(2)}`
    },
    { 
      Header: 'Change', 
      accessor: 'change',
      Cell: ({ value }: { value: number }) => (
        <span className={value >= 0 ? 'text-green-600' : 'text-red-600'}>
          {value}%
        </span>
      )
    },
  ], []);

  // Table logic implementation...
  return (
    <div className="overflow-x-auto shadow-md sm:rounded-lg">
      <table className="min-w-full text-sm text-left text-gray-500">
        <thead className="text-xs text-gray-700 uppercase bg-gray-50">
          {/* Header Rows */}
        </thead>
        <tbody>
          {/* Data Rows */}
        </tbody>
      </table>
    </div>
  );
};

The difference is stark. The React version is more accessible, easier to style, and runs natively in any modern browser without plugins.

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Why "Visual Reverse Engineering" is Winning in Financial Services#

Traditional silverlight react migration platforms focus on the code. But in financial services, the code is often the problem. Years of patches, "spaghetti" logic, and deprecated libraries make direct transpilation a nightmare.

Replay's approach of visual reverse engineering bypasses the "code rot." By focusing on the UI and the user experience, it allows financial institutions to:

1. •Standardize Design Systems: Instead of having 50 different styles of buttons across 10 migrated apps, Replay identifies patterns and creates a unified Design System in React.
2. •Clean the Slate: It allows teams to keep the business logic (which can be moved to modern .NET APIs) while completely modernizing the frontend without being shackled to legacy XAML constraints.
3. •Accelerate Documentation: Replay doesn't just give you code; it gives you a documented component library. This is crucial for SOC2 compliance and internal audits.

The Role of AI in Migration#

Modern migration platforms are increasingly using LLMs (Large Language Models) to assist in the conversion. However, AI is only as good as its context. A tool that looks at a static snippet of C# code might miss how a component actually behaves when a user interacts with it. Replay provides that behavioral context by recording the application in motion, ensuring the React output isn't just syntactically correct, but functionally identical.

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Strategic Steps for a Successful Silverlight to React Migration#

If you are overseeing a migration within a bank or insurance firm, follow this roadmap:

Step 1: Inventory and Prioritization#

Not all Silverlight apps are created equal. Use a "Complexity vs. Business Value" matrix. High-value, high-complexity apps should be the first candidates for a platform like Replay to ensure no functionality is lost.

Step 2: Choose Your Migration Strategy#

• •The "Big Bang": Full rewrite using a platform like Mobilize.Net or Replay.
• •The "Strangler Pattern": Use OpenSilver to host the app, then slowly replace individual pages with React components.

Step 3: Define the Design System#

One of the biggest mistakes in migration is recreating the "look" of 2008 in 2024. Use the migration as an opportunity to implement a modern Design System. Tools like Replay are specifically designed to extract these patterns and turn them into a reusable React library.

Step 4: Data Layer Modernization#

Silverlight often relied on WCF (Windows Communication Foundation) or RIA Services. These must be migrated to RESTful APIs or GraphQL. Ensure your chosen silverlight react migration platforms can handle the data-binding shifts required.

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Security Considerations for Financial Migrations#

In the financial sector, security is paramount. Silverlight's security model was based on the browser plugin sandbox, which is now obsolete. When moving to React, you must implement:

• •Content Security Policy (CSP): To prevent XSS attacks that were less common in the Silverlight era.
• •JWT or OAuth2 Authentication: To replace legacy Windows Authentication or custom SOAP-based auth.
• •Input Validation: React’s state management provides a great opportunity to harden input validation that was previously handled by the .NET runtime.

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FAQ: Navigating Silverlight React Migration Platforms#

How long does a typical Silverlight to React migration take?#

For a medium-sized financial application (50-100 screens), a manual rewrite can take 12-18 months. Using automated silverlight react migration platforms like Mobilize.Net or visual tools like Replay can reduce this by 40-60%, often bringing the timeline down to 6-9 months.

Can we migrate Silverlight's complex DataGrids to React?#

Yes. Modern React libraries like AG Grid or TanStack Table are actually more powerful than the original Silverlight DataGrid. Platforms like Replay can map the properties of your legacy grids to these modern libraries automatically.

Do I need the original Silverlight source code to migrate?#

While having the source code is helpful for backend logic, visual migration platforms like Replay can reconstruct the entire frontend and component architecture just by analyzing a recording of the running application. This is a lifesaver for firms that have lost access to legacy source repositories.

What is the cost difference between OpenSilver and a full React migration?#

OpenSilver is generally cheaper in the short term because it requires less rewriting. However, a full React migration provides a much higher ROI by reducing long-term maintenance costs, improving performance, and making it easier to hire developers.

Why is React preferred over Angular or Vue for Silverlight migrations?#

React’s ecosystem is the primary driver. Financial services require specialized components (advanced charting, real-time data grids, complex forms), and the React ecosystem (with tools like Replay, AG Grid, and Highcharts) offers the most robust versions of these tools.

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The Definitive Choice for Modern FinTech#

The era of browser plugins is over. For financial institutions, the move to React is not just a trend—it's a requirement for survival. While there are many silverlight react migration platforms available, the best approach is one that minimizes risk, preserves UI intent, and results in a maintainable, high-quality codebase.

If you are looking to convert your legacy Silverlight applications into documented, high-performance React code without the headache of manual rewrites, it's time to look at visual reverse engineering.

Ready to see your legacy UI transformed into a modern React Design System? Explore Replay (replay.build) and start your migration today.