Java
以下排序是按照从技术组件到开发框架到代码工具，也有一些实在不好分类的，就放到最后了。

WEB 容器

Tomcat

https://tomcat.apache.org/

Jetty

https://www.jetty.com/

JBoss

https://www.jboss.org/

Resin

https://caucho.com/products/resin

数据库

H2

https://h2database.com/

SQLite

https://www.sqlite.org/

MySQL

https://www.mysql.com/

Oracle

https://www.oracle.com/index.html

SQL Server

https://www.microsoft.com/en-us/sql-server/sql-server-downloads

PostgreSQL

https://www.postgresql.org/

MariaDB

https://mariadb.org/

缓存

Redis

https://redis.io/

Memcached

https://memcached.org/

消息队列

Kafka

https://kafka.apache.org/

RocketMQ

https://rocketmq.apache.org/

Pulsar

https://pulsar.apache.org/

RabbitMQ

https://www.rabbitmq.com/

负载均衡

LVS

http://www.linuxvirtualserver.org/

NGINX

https://www.nginx.com/

分布式存储

Ceph

https://docs.ceph.com/

HDFS

https://hadoop.apache.org/docs/r1.2.1/hdfs_design.html

数据库集群

MHA

https://github.com/yoshinorim/mha4mysql-manager

分布式协调

ZooKeeper

https://zookeeper.apache.org/

大数据相关

Storm

https://storm.apache.org/

Flink

https://flink.apache.org/

Spark

https://spark.apache.org/

HBase

https://hbase.apache.org/

Flink

https://flink.apache.org/

ClickHouse

https://clickhouse.com/

Doris

https://doris.apache.org/

日志收集与分析

Filebeat

https://www.elastic.co/beats/filebeat

Logstash

https://www.elastic.co/logstash/

Kibana

https://www.elastic.co/kibana

搜索

Elasticsearch

https://www.elastic.co/

系统监控

SkyWalking

https://skywalking.apache.org/

zipkin

https://zipkin.io/

分库分表

ShardingSphere

https://shardingsphere.apache.org/

Mycat2

http://mycatone.top/

微服务

Spring Cloud

https://spring.io/projects/spring-cloud

RPC 框架

Dubbo

https://github.com/apache/dubbo

gRPC

https://github.com/grpc/grpc-java

网络框架

Netty

https://netty.io/

MVC 框架

Spring Framework

https://spring.io/projects/spring-framework

Spring Boot

https://spring.io/projects/spring-boot

数据层框架

MyBatis

https://github.com/mybatis/mybatis-3

MyBatis-Plus

https://github.com/baomidou/mybatis-plus

Hibernate

http://hibernate.org/orm/

数据库连接池

HikariCP

https://github.com/brettwooldridge/HikariCP

Druid

https://github.com/alibaba/druid

Redis 客户端

Jedis

https://github.com/xetorthio/jedis

Redisson

https://github.com/redisson/redisson

Rest 接口设计与开发

Swagger

https://swagger.io/

数据参数校验

Hibernate Validator

https://hibernate.org/validator/

安全相关

Shiro

https://shiro.apache.org/

Bouncy Castle

https://www.bouncycastle.org/java.html

jjwt

https://github.com/jwtk/jjwt

Reactive 编程

Akka

https://akka.io/

RxJava

https://github.com/ReactiveX/RxJava

vert.x

https://vertx.io/

单元测试

JUnit

https://junit.org/junit5/

测试辅助

JMockit

http://jmockit.github.io/

Mockito

https://github.com/mockito/mockito

JMeter

http://jmeter.apache.org/

Selenium

https://www.selenium.dev/

日志记录

Log4j2

https://logging.apache.org/log4j/

Logback

http://logback.qos.ch/

SLF4J

http://www.slf4j.org/

代码质量检查

Checkstyle

https://github.com/checkstyle/checkstyle

Spotbugs

https://github.com/spotbugs/spotbugs

代码生成

Lombok

https://projectlombok.org/

领域语言定制

ANTLR

https://www.antlr.org/

配置文件解析

config

https://github.com/lightbend/config

序列化格式

Avro

https://avro.apache.org/

Thrift

https://thrift.apache.org/

Protobuf

https://github.com/protocolbuffers/protobuf

模板引擎

Freemarker

https://freemarker.apache.org/

Thymeleaf

https://www.thymeleaf.org/

Office 文档处理

POI

https://poi.apache.org/

PDF 处理

iText

https://itextpdf.com/en

Apache PDFBox

https://pdfbox.apache.org/

高性能队列

Disruptor

https://lmax-exchange.github.io/disruptor/

HTTP 客户端

Async Http Client

https://github.com/AsyncHttpClient/async-http-client

Feign

https://github.com/OpenFeign/feign

Retrofit

https://square.github.io/retrofit/

二维码解析

ZXing

https://github.com/zxing/zxing

定时任务调度

Quartz

https://github.com/quartz-scheduler/quartz

JSON 解析

Gson

https://github.com/google/gson

Jackson

https://github.com/FasterXML/jackson

fastjson

https://github.com/alibaba/fastjson

分布式事务

Seata

https://github.com/seata/seata

属性映射

MapStruct

https://github.com/mapstruct/mapstruct

本地缓存

Ehcache

http://www.ehcache.org/

Caffeine

https://github.com/ben-manes/caffeine

系统排错与调优

JMH

http://openjdk.java.net/projects/code-tools/jmh/

Arthas

https://github.com/alibaba/arthas

命令行参数解析

JCommander

http://jcommander.org/

计算机视觉

JavaCV

https://github.com/bytedeco/javacv

工具集合

Guava

https://github.com/google/guava

Hutool

https://hutool.cn/

构建工具

Maven

https://maven.apache.org/

Gradle

https://gradle.org/

Bazel

https://bazel.build/

本地系统开发

JNA

https://github.com/java-native-access/jna

JVM

Adopt Open JDK

https://adoptopenjdk.net/

Graal

https://github.com/oracle/graal

Open JDK

https://openjdk.java.net/

多版本 Java 支持

jenv

https://github.com/jenv/jenv

爬虫相关

Nutch

https://nutch.apache.org/

Crawler4j

https://github.com/yasserg/crawler4j

jsoup

https://jsoup.org/

webmagic

https://github.com/code4craft/webmagic