Software Alternatives, Accelerators & Startups

OpenSilver VS RepDB

Compare OpenSilver VS RepDB and see what are their differences

Note: These products don't have any matching categories. If you think this is a mistake, please edit the details of one of the products and suggest appropriate categories.

OpenSilver logo OpenSilver

Open-source re-implementation of Silverlight on modern browsers using WebAssembly.

RepDB logo RepDB

Exercise dataset for fitness apps: transparent background, animations, no subscription
Visit Website
  • OpenSilver Landing page
    Landing page //
    2022-11-18
  • RepDB
    Image date //
    2026-07-21
  • RepDB Landing page
    Landing page //
    2026-07-21
  • RepDB
    Image date //
    2026-07-21

RepDB is a one-time-purchase exercise dataset for developers building fitness and workout apps โ€” not a subscription, not a rate-limited API. You download the data once and own it: JSON (and SQLite on the higher tier), WebP images, and full EN/DE/ES translations, with no per-request billing and no dependency on our servers staying up.

A free tier includes 400 exercises with flat-style 512ร—512 images, attribution-licensed for commercial in-app use. The Starter tier ($199) adds the full catalog in classic white-background style. Standard ($399) adds transparent 1024px images, looping animations, exercise relations (similar/progressions/regressions), workout templates, and embeddings โ€” exclusive to that tier.

Every exercise includes muscle-group highlighting, equipment/muscle icons, MET values, and safety/goal tags. Compared to GIF- or JPG-based competitor APIs, RepDB images are transparent WebP with no watermarks, so they drop into any app UI without a white box around them.

OpenSilver

Pricing URL
-
$ Details
-
Platforms
-
Release Date
-

RepDB

Website
repdb.co
$ Details
freemium $199.0 / One-off
Platforms
Web Mobile
Release Date
2026 July

OpenSilver features and specs

  • Cross-Platform Compatibility
    OpenSilver enables developers to create applications that run on multiple platforms, including web browsers, by leveraging WebAssembly, which enhances the reach and accessibility of applications originally written in Silverlight.
  • Silverlight Code Reusability
    Since OpenSilver supports C# and XAML, much of the existing Silverlight code can be reused, minimizing migration efforts and reducing time and costs associated with redevelopment.
  • WebAssembly Based Performance
    By utilizing WebAssembly, OpenSilver applications can achieve near-native performance, leading to efficient and responsive user experiences in web applications.
  • Open Source Flexibility
    As an open-source project, OpenSilver offers developers the ability to contribute to and modify the platform, fostering a community-driven environment and encouraging innovation.
  • Integration with Modern Web Technologies
    OpenSilver allows integration with modern web technologies and frameworks, enabling developers to enhance applications with contemporary features and functionalities.

Possible disadvantages of OpenSilver

  • Incomplete Feature Support
    Not all of Silverlight's features are fully supported in OpenSilver, which might necessitate additional workarounds or re-implementations for complex applications.
  • Learning Curve for Migration
    Developers familiar with Silverlight may need to learn new patterns and practices related to web development and WebAssembly when transitioning to OpenSilver.
  • Browser Compatibility
    While WebAssembly aims to be universally compatible, some differences in performance and behavior might occur across various browsers, potentially requiring additional testing and optimization.
  • Community and Support Maturity
    As a relatively new and open-source project, OpenSilver might have a less mature support ecosystem compared to more established platforms, impacting the availability of resources and community support.
  • Dependency on WebAssembly
    OpenSilver's reliance on WebAssembly means that any limitations or ongoing development challenges associated with WebAssembly could directly impact the capabilities and performance of OpenSilver applications.

RepDB features and specs

  • WebP Format Benefits
    start+peak exercise images
  • JSON
    relations, metadata, equipment
  • Transparency
    transparent background
  • Animations
    Animated loops in paid tier

Category Popularity

0-100% (relative to OpenSilver and RepDB)
Online Services
100 100%
0% 0
Datasets
0 0%
100% 100
Product Presentation
100 100%
0% 0
Developer Tools
0 0%
100% 100

Questions & Answers

As answered by people managing OpenSilver and RepDB.

What makes your product unique?

RepDB's answer:

RepDB is sold as a one-time download, not a metered API โ€” you own the JSON/SQLite data and WebP images outright, with no rate limits, no per-request billing, and no risk of the vendor cutting off access. It's also the only dataset in this space with EN/DE/ES translations, transparent (alpha-channel) images with no watermark, muscle-group highlighting, safety/goal tags, and looping animations on the higher tier.

What's the story behind your product?

RepDB's answer:

RepDB grew out of a consumer workout app its creator was building solo. Sourcing exercise images and data meant either paying for a subscription API with usage caps and no caching rights, or producing everything from scratch. The illustrated, multi-language dataset was built for us first, then split out as its own product once it became clear other indie developers had the same problem and preferred to buy the data outright rather than rent it through an API.

Why should a person choose your product over its competitors?

RepDB's answer:

Most alternatives are subscription APIs โ€” you pay monthly, you're capped on requests, and ExerciseDB's terms of use explicitly forbid caching or storing the data at all, so every image render is a live paid API call. RepDB is the opposite: pay once, download the files, self-host with zero ongoing dependency. It's also the only option offering true DE/ES localization and transparent images instead of a white box behind every exercise.

How would you describe the primary audience of your product?

RepDB's answer:

Solo developers and small teams building fitness or workout-tracking apps (iOS, Android, web) who need licensed exercise images and structured exercise data, but don't want to build their own media pipeline or depend on a rate-limited third-party API.

User comments

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Social recommendations and mentions

Based on our record, OpenSilver seems to be more popular. It has been mentiond 13 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.

OpenSilver mentions (13)

  • Show HN: Browser-based .NET IDE with visual designer, NuGet packages, code share
    - XAML autocompletion, AI error fixing, split editor views The visual designer is the differentiator: 100+ drag-and-drop controls for building UIs. But the NuGet and sharing features work even if you ignore the designer entirely and just write C# code. XAML.io is currently in tech preview. It's built on OpenSilver (https://opensilver.net), a from-scratch reimplementation of the WPF API (subset) using modern .NET,... - Source: Hacker News / 5 months ago
  • .NET MAUI Is Coming to Linux and the Browser, Powered by Avalonia
    Beside already mentioned, there is OpenSilver[1]. Supports Silvelight and WPF. Renders to DOM+WASM. They are also planning support for MAUI. [1] https://opensilver.net/. - Source: Hacker News / 9 months ago
  • Revisiting WASM for F#
    I would also say that IF blazor worked on a browser plugin like silverlight did, today that's not the case it is built on the webassembly standard which and it is being adopted in the browsers which means once it gets on the web, it is unlikely to ever go out again. Even if Microsoft themselves leave Blazor today, it can still work, the burden of creating a fork and keeping blazor alive will certainly be big but... - Source: dev.to / over 2 years ago
  • Seeking Advice on Product Positioning for new .NET-based SDK/Framework
    Under the Hood: Technically, XR# integrates Three.js, A-Frame.js, and the Microsoft .NET to WASM compiler (like in Blazor). Itโ€™s built on our decade-long experience with OpenSilver, a contemporary Silverlight alternative. Source: almost 3 years ago
  • WASI: A New Kind of System Interface
    Nah, I appreciate the wonderfull work of those WebAssembly people that allowed me to have Java applets, Flash and Silverligh running again in the browser. https://leaningtech.com/cheerpj/ https://leaningtech.com/cheerpx-for-flash/ https://opensilver.net/ Thanks for making the revenge of plugins a reality. - Source: Hacker News / over 4 years ago
View more

RepDB mentions (0)

We have not tracked any mentions of RepDB yet. Tracking of RepDB recommendations started around Jul 2026.

What are some alternatives?

When comparing OpenSilver and RepDB, you can also consider the following products

Flash Player 2021 - Want to fix "This plugin is not supported" and "Adobe Flash Player is blocked" error messages? This extension will remove those messages and allow you to play Flash in any website with a single click.

SuperNova Player - SuperNova Player allows systems to play .SWF files in a standalone player launched from any browser.

X (Twitter) - Connect with your friends and other fascinating people. Get in-the-moment updates on the things that interest you. And watch events unfold, in real time, from every angle.

Newgrounds Player - Can play Flash files offline.

CheerpX for Flash - its adobe flash player in webassembly

Ruffle - An open source Flash player