What earns a recommendation
We look for a clear purpose, identifiable publisher, substantive accessible material, and a useful contribution to its category. Primary documentation, public institutions, and specialist resources are preferred when they answer the task directly.
How to read our notes
Recommendation notes explain selection reasons, useful features, intended audiences, and limitations. They are editorial judgments based on the linked source, not user ratings. A source-check date records research, not a promise of continuous monitoring or a hands-on product test.
Maintaining quality
Before adding a resource, check its destination and describe a concrete use case. Recheck entries when a broken link, changed service, or factual error is identified. Remove or revise entries that no longer meet these criteria. Collection order reflects the task, not a numerical ranking.