톰캣은 서블릿 컨테이너이며, 자바 서블릿 Java Servlet과 자바서버 페이지JavaServer Pages 기술에 대한 공식적인 참조 구현체입니다. 자바 서블릿과 자바서버 페이지 스펙은 Java Community Process 주도하에 썬에 의해서 개발됩니다.

톰캣은 아파치 소프트웨어 라이센스 아래 공개적이고 함께 하는 환경에서 개발되고 배포됩니다. 톰캣은 전세계의 베스트 개발자들의 합작으로 의도된 것입니다. 이런 공개개발 프로젝트에 당신을 초대합니다. 참가하기 위해 필요한 자세한 정보는 여기를 클릭하세요.

우선, 현재 배포된 톰캣 제품 버전과 서블릿/JSP 스펙에 대한 비교표입니다:

Servlet/JSP Spec	톰캣 버전
2.4/2.0	5.0.12 Beta
2.3/1.2	4.1.27
2.2/1.1	3.3.1a

어떤 버전을 써야할 지에 대한 선택을 돕기 위해서 배포 버전에 대해 좀 더 자세히 설명해 놓았습니다. 각 버전에 대한 더 자세한 내용은 각 배포판에 있는 릴리스 노트 파일에 나와있습니다.

Tomcat 5.x

톰캣 5.x은 톰캣 배포판의 주류로 떠오르는 버전입니다. 이것은 톰캣 3.3 과 톰캣 4.1 코드기반으로 만들어져 있습니다. 5.x버전은 서블릿 2.4 와 JSP 2.0 스펙을 구현합니다. 톰캣 5.0.x. 톰캣 5.0은 4.1버전을 여러 방면에서 개선했습니다. 개선점은 다음과 같습니다: 성능 최적화와 가비지 컬렉션 감소 리팩토링된 어플리케이션 배치기능. 정식으로 서비스하기 전에 웹 어플리케이션의 오류검사(validation)와 컴파일(compilation)을 지원하는 선택적인 독립 배치기능이 있습니다. JMX와 매니저 웹 어플리케이션을 사용한 완벽한 서버 모니터링 기능 확장성(Scalability)과 신뢰성(reliability) 향상 진보된 풀링과 태그 플러그인과 같이, 향상된 태그라이브러리 처리 Improved platform integration, with native Windows and Unix wrappers Embedding of Tomcat using JMX Enhanced Security Manager support Integrated session clustering Expanded documentation

Tomcat 4.x

Tomcat 4.x implements a new servlet container (called Catalina) that is based on completely new architecture. The 4.x releases implement the Servlet 2.3 and JSP 1.2 specifications. Tomcat 4.1.x. Tomcat 4.1.27 Stable is the latest release. Tomcat 4.1 is a refactoring of Tomcat 4.0.x, and contains significant enhancements, including: JMX based administration features JSP and Struts based administration web application New Coyote connector (HTTP/1.1, AJP 1.3 and JNI support) Rewritten Jasper JSP page compiler Performance and memory efficiency improvements Enhanced manager application support for integration with development tools Custom Ant tasks to interact with the manager application directly from build.xml scripts Tomcat 4.0.x. Tomcat 4.0.6 is the old production quality release. Tomcat 4.0 is the next generation of Tomcat. The 4.0 servlet container (Catalina) has been developed from the ground up for flexibility and performance. Version 4.0 implements the final released versions of the Servlet 2.3 and JSP 1.2 specifications. As required by the specifications, Tomcat 4.0 also supports web applications built for the Servlet 2.2 and JSP 1.1 specifications with no changes.

Tomcat 3.x

There are several versions of Tomcat 3.x currently available for download: Version 3.3 is the current production quality release for the Servlet 2.2 and JSP 1.1 specifications. Tomcat 3.3 is the latest continuation of the Tomcat 3.x architecture and it is more advanced then 3.2.4, which is the 'old' production quality release. Version 3.2.4 is the 'old' production quality release and is now in maintenance only mode. Version 3.1.1 is a legacy release. All Tomcat 3.x releases trace their heritage back to the original Servlet and JSP implementations that Sun donated to the Apache Software Foundation. The 3.x versions all implement the Servlet 2.2 and JSP 1.1 specifications. Tomcat 3.3.x. Version 3.3.1 is the current production quality release. It continues the refactoring that was begun in version 3.2 and carries it to its logical conclusion. Version 3.3 provides a much more modular design and allows the servlet container to be customized by adding and removing modules that control the processing of servlet requests. This version also contains many performance improvements. Tomcat 3.2.x. Version 3.2 added few new features since 3.1; the major effort was a refactoring of the internals to improve performance and stability. The 3.2.1 release, like 3.1.1, was a security patch. Version 3.2.2 fixed a large number of bugs and all known specification compliance issues. Version 3.2.3 was a security update that closes a serious security hole. Version 3.2.4 is a minor bug fix release. All users of Tomcat versions prior to 3.2.3 should updgrade as soon as possible. With the exception of fixes for critical security related bugs, development on the Tomcat 3.2.x branch has stopped. Tomcat 3.1.x. The 3.1 release contained several improvements over Tomcat 3.0, including servlet reloading, WAR file support and added connectors for the IIS and Netscape web servers. The latest maintenance release, 3.1.1, contained fixes for security problems. There is no active development ongoing for Tomcat 3.1.x. Users of Tomcat 3.1 should update to 3.1.1 to close the security holes and they are strongly encouraged to migrate to the current production release, Tomcat 3.3. Tomcat 3.0.x. Initial Tomcat release.