Laravel Extendable Basket provides several abstract classes that implement basic ecommerce basket functionality
An abstract repository class for your Eloquent repositories that requires minimal config to get started.
A base repository class for Eloquent to abstract away persistence layer from your business code
Interface and abstract class - simple and easy explanation
Laravel 5 - Repositories to abstract the database layer
Infection Abstract Test Framework Adapter
PHP library for transactional Key-Value, Key-Object, Queue sharded storages on MySQL/Mongo/Redis/Memcached