An abstract framework for reconciling source files into diagnostics. Defines a `ReconcileEngine` interface and companion classes (`ProblemType`, `ProblemTypeParameter`, `ICollector`) that are reused across multiple language servers (Boot, YAML, Concourse, XML). The pattern isolates the reconciliation logic from IDE-specific notification, making it extractable and testable. Demonstrates clean separation of concerns for LSP diagnostics.

A caching AST provider for YAML documents that supports incremental parsing and invalidation on file change. Manages a `YamlParser` and keeps parsed ASTs in a soft-reference cache. Designed to be reused by any YAML-based language server (e.g., Concourse, Manifest YAML). The pattern of caching ASTs with document version tracking is a common requirement that can be extracted and adapted for other structured document formats.

A reactive value holder and expression evaluator for Eclipse UI models. `LiveExpression<T>` provides observable values, derived expressions, and validation message propagation. It is used extensively across Boot Dash, wizards, and property pages. The implementation is self-contained (no dependency on internal Eclipse APIs beyond basic SWT) and could be extracted as a standalone reactive framework for Eclipse RCP applications.