JAR Hell

JAR hell refers to a set of problems arising from Java's class loading mechanism: unexpressed dependencies, transitive dependencies, shadowing, version conflicts, and complex class loading. Build tools like Maven largely solve unexpressed and transitive dependency issues but do little about shadowing or version conflicts. Component systems like OSGi can address most problems but add complexity and are rarely used. Version conflicts remain the most persistent and impactful problem in practice, often dictating when and how dependencies can be updated in real projects.