PaperMC/Velocity

CS-Notes is a GitHub repository maintained by CyC2018 that collects Chinese-language study notes across ten topic areas: algorithms, operating systems, networking, object-oriented design, databases, Java, system design, tools, coding practice, and an afterword. It links each topic to standalone markdown files instead of writing everything inline, and the README says most of the content is original work rather than material copied from elsewhere.

Java Design Patterns is an open-source GitHub project by iluwatar that documents design patterns as commented, working Java code rather than diagrams or prose. The repository is organized so readers can find a pattern by name, by tag such as Gang of Four or Performance, or by category, with a companion site and an optional paid e-book alongside it.

Spring Boot is an opinionated layer on top of Spring that handles the boilerplate you'd otherwise write for every project — auto-configuration for embedded servers, security, metrics, and health endpoints — so you can ship a runnable JAR with `java -jar` without touching XML. The trade-off is that you're buying into Spring's conventions hard; when your requirements genuinely diverge from the defaults, the "get out of the way" promise only goes so far and you're still digging through Spring's layered configuration model. It genuinely skips code generation and XML, which is rare for a framework this feature-complete, and the Gradle-based build with JDK 25 requirement tells you this is aimed at teams with a modern JVM already in place.

The Algorithms - Java is a community-maintained GitHub repository collecting Java implementations of sorting algorithms, search algorithms, and core data structures, organized for study rather than production use.