buji-pac4j is a bridge library that integrates pac4j (a comprehensive security library supporting OAuth, CAS, SAML, OpenID Connect, etc.) with Apache Shiro. It automatically pushes pac4j authentication and authorization profiles into the Shiro security context, allowing developers to use pac4j's wide range of authentication mechanisms while leveraging Shiro for authorization and session management. The bridge is implemented as a set of classes that adapt pac4j's session store, profile manager, and framework adapter to Shiro's APIs, plus a custom Realm, SubjectFactory, and Token. It includes sophisticated logic to avoid unnecessary session renewal when the same user's profiles are updated (e.g., after token refresh), demonstrating deep understanding of both frameworks' internals. The library is production-ready, actively maintained, and used in legacy applications that want to adopt pac4j without fully migrating away from Shiro.
MaxKey is an enterprise-grade Identity and Access Management (IAM) / Single Sign-On (SSO) platform written in Java (Spring Boot) with Angular frontends. It supports a comprehensive set of authentication protocols (OAuth 2.0/OpenID Connect, SAML 2.0, CAS, JWT, form-based, token-based) and identity federation standards (SCIM 2.0, LDAP, Active Directory). The codebase is organized as a multi-module Maven project with clear separation between authentication providers, protocol implementations, persistence layer, and web UIs. Architecturally, it follows a service-oriented model with a custom OAuth2 stack (derived from Spring Security OAuth), MyBatis JPA for persistence, and Redis/Caffeine for caching. The frontends are built on NG-ALAIN (Angular 17) and share a common base for user portal and admin console. While the system is functionally rich and actively maintained, it contains some duplicated code across modules and relies on a legacy OAuth2 implementation that has been superseded by Spring Security 5+. The crypto utilities, OTP infrastructure, and adapter patterns are well-structured and demonstrate non-obvious craftsmanship.
Algebrite is a symbolic mathematics library (Computer Algebra System) written in TypeScript. It provides a comprehensive set of operations including symbolic differentiation, integration, polynomial factorization, root finding, matrix/tensor algebra, arbitrary-precision arithmetic, and expression simplification. Internally, it uses an S-expression representation (Cons cells) and a recursive-descent parser to convert string expressions into algebraic trees. The library exposes both a string-based `run()` API for evaluating expressions and direct method calls (e.g., `Algebrite.factor`). It was originally forked from EigenMath and retains some CoffeeScript legacy in test files and debug logging. The codebase is large and monolithic, with many modules tightly coupled through shared global state (the `defs` object). Despite this, the implementation is functional and covers a wide range of mathematical operations, making it suitable for embedding in interactive notebooks or computational tools.