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Top 23 Java Kotlin Projects
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Just to throw one on the pile https://github.com/yuliskov/smarttube for android based TV media box is great.
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InfluxDB
InfluxDB – Built for High-Performance Time Series Workloads. InfluxDB 3 OSS is now GA. Transform, enrich, and act on time series data directly in the database. Automate critical tasks and eliminate the need to move data externally. Download now.
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android-interview-questions
Your Cheat Sheet For Android Interview - Android Interview Questions and Answers
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- Project mention: MAML – a new configuration language (similar to JSON, YAML, and TOML) | news.ycombinator.com | 2025-10-12
The other deserving a mention is Pkl. Common denominator of being backed by a FAANG and having a lot of real world use.
https://github.com/apple/pkl
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glide-transformations
An Android transformation library providing a variety of image transformations for Glide.
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Stream
Stream - Scalable APIs for Chat, Feeds, Moderation, & Video. Stream helps developers build engaging apps that scale to millions with performant and flexible Chat, Feeds, Moderation, and Video APIs and SDKs powered by a global edge network and enterprise-grade infrastructure.
- Project mention: Applying API Testing Frameworks: Real-World Examples with Swagger and JUnit | dev.to | 2025-11-03
Swagger Documentation JUnit 5 Documentation RestAssured Documentation Top 15 API Testing Tools in 2022
- Project mention: Micronaut 4 application on AWS Lambda- Part 1 Introduction to the sample application and first Lambda performance measurements | dev.to | 2025-07-14
In this application, we will create products and retrieve them by their ID and use Amazon DynamoDB as a NoSQL database for the persistence layer. We use Amazon API Gateway which makes it easy for developers to create, publish, maintain, monitor and secure APIs and AWS Lambda to execute code without the need to provision or manage servers. We also use AWS SAM, which provides a short syntax optimised for defining infrastructure as code (hereafter IaC) for serverless applications. For this article, I assume a basic understanding of the mentioned AWS services, serverless architectures in AWS, Micronaut framework and GraalVM including its Native Image capabilities.
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- Project mention: Automating Serialization/Deserialization Tests with Orkes Conductor and LLMs | dev.to | 2025-05-29
Run Spotless to auto-format the code for style consistency.
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LWJGL
LWJGL is a Java library that enables cross-platform access to popular native APIs useful in the development of graphics (OpenGL, Vulkan, bgfx), audio (OpenAL, Opus), parallel computing (OpenCL, CUDA) and XR (OpenVR, LibOVR, OpenXR) applications.
You see, for the past several years I have used many programming languages and many more game frameworks and libraries. Programming languages like Java, C#, C++, and even, sadly, JavaScript (I know...). Game frameworks like LWJGL, SDL2, Raylib, MonoGame, SFML, and many more. Essentially, I have seen it all. Out of all of them, I think SDL2 was closer to what I was looking for, though, Raylib was the one I used the most at the beginning. And the reason I liked SDL more was because it was more"lower-level" than Raylib or SFML. Additionally, it had that C-style of programming that I have always been fond of. However, despite that, I decided to go against any of these libraries.
- Project mention: YouTube Forces Ads in Moldova Without Offering Premium as an Option | news.ycombinator.com | 2025-03-07
On Android, you can use ReVanced [1] to patch the YouTube app (and much more) on your own device. It's safer than looking for "modded APKs" online as you can see the source of the patches you apply to your own app [2]
[1] https://revanced.app/
[2] https://github.com/revanced/revanced-patches/
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ObjectBox Java (Kotlin, Android)
Database for Android and JVM - first and fast, lightweight on-device vector database
Project mention: Will Amazon S3 Vectors Kill Vector Databases–Or Save Them? | news.ycombinator.com | 2025-09-08It would be great to have the vector database run on the edge / on-device for offline-first and privacy-focused. https://objectbox.io/ does a good job of this but are there others?
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- Project mention: Energy-Efficient Schema-Driven Development with Spring WebMVC/WebFlux | dev.to | 2025-04-20
In Spring WebMVC/WebFlux, you can use springdoc-openapi to automatically generate an OpenAPI schema from Spring controller implementations. Having an OpenAPI schema enables automatic generation of HTML documentation and client code, which already provides some value.
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LeafPic
LeafPic is a fluid, material-designed alternative gallery, it also is ad-free and open source under GPLv3 license. It doesn't miss any of the main features of a stock gallery, and we also have plans to add more useful features. (by UnevenSoftware)
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SaaSHub
SaaSHub - Software Alternatives and Reviews. SaaSHub helps you find the best software and product alternatives
NOTE: The open source projects on this list are ordered by number of github stars. The number of mentions indicates repo mentiontions in the last 12 Months or since we started tracking (Dec 2020).
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Hey, I did a thing, you might like it! Java JSpecify Exercise
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Configuration files are user interfaces
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Exploring Firestore with Micronaut and Java 21: A Scalable NoSQL Solution for Modern Applications
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Automating Serialization/Deserialization Tests with Orkes Conductor and LLMs
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Spring Boot with Spotless and Git Pre-commit Hooks
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Top Backend Technologies for Scalable Web Development
- A note from our sponsor - Stream getstream.io | 23 Dec 2025
Index
What are some of the best open-source Kotlin projects in Java? This list will help you:
| # | Project | Stars |
|---|---|---|
| 1 | SmartTube | 27,018 |
| 2 | android-interview-questions | 12,216 |
| 3 | GmsCore | 11,634 |
| 4 | Permission Dispatcher | 11,223 |
| 5 | pkl | 10,985 |
| 6 | glide-transformations | 9,926 |
| 7 | REST Assured | 7,087 |
| 8 | junit-framework | 6,929 |
| 9 | Micronaut | 6,365 |
| 10 | from-java-to-kotlin | 6,317 |
| 11 | Suwayomi-Server | 6,183 |
| 12 | Blurry | 5,665 |
| 13 | spotless | 5,211 |
| 14 | LWJGL | 5,198 |
| 15 | revanced-patches | 5,081 |
| 16 | dialogplus | 4,985 |
| 17 | Android Tips & Tricks | 4,753 |
| 18 | ObjectBox Java (Kotlin, Android) | 4,576 |
| 19 | JaCoCo | 4,460 |
| 20 | springdoc-openapi | 3,646 |
| 21 | vertx-examples | 3,577 |
| 22 | AutoDispose | 3,368 |
| 23 | LeafPic | 3,276 |
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