FindBugs
FindBugs is an open-source static code analyser created by Bill Pugh and David Hovemeyer which detects possible bugs in Java programs. Potential errors are classified in four ranks: (i) scariest, (ii) scary, (iii) troubling and (iv) of concern. This is a hint to the developer about their possible impact or severity. FindBugs operates on Java bytecode, rather than source code. The software is distributed as a stand-alone GUI application. There are also plug-ins available for Eclipse, NetBeans, IntelliJ IDEA, Gradle, Hudson, Maven, Bamboo and Jenkins. Additional rule sets can be plugged in FindBugs to increase the  set of checks performed. SpotBugs. SpotBugs is the spiritual successor of FindBugs, carrying on from the point where it left off with support of its community. In 2016, the project lead of FindBugs was inactive but there are many issues in its community so Andrey Loskutov gave an announcement to its community, and some volunteers tried creating a project with support for modern Java platform and better maintainability. In 2017 Sep, Andrey Loskutov again gave an announcement about the status of new community, then released SpotBugs 3.1.0 with support for Java 11 the new LTS, especially Java Platform Module System  and codice_1 instruction. There are also plug-ins available for Eclipse, IntelliJ IDEA, Gradle, Maven and SonarQube. SpotBugs also supports all of existing FindBugs plugins such as sb-contrib,<ref>