Yesod vs Yii: What are the differences?
Developers describe Yesod as "A RESTful Haskell web framework built on WAI". Yesod believes in the philosophy of making the compiler your ally, not your enemy. We use the type system to enforce as much as possible, from generating proper links, to avoiding XSS attacks, to dealing with character encoding issues. In general, if your code compiles, it works. And instead of declaring types everywhere you let the compiler figure them out for you with type inference. On the other hand, Yii is detailed as "A high-performance PHP framework best for developing Web 2.0 applications". Yii comes with: MVC, DAO/ActiveRecord, I18N/L10N, caching, authentication and role-based access control, scaffolding, testing, etc. It can reduce your development time significantly.
Yesod and Yii can be categorized as "Frameworks (Full Stack)" tools.
"Haskell" is the primary reason why developers consider Yesod over the competitors, whereas "Open source" was stated as the key factor in picking Yii.
Yesod and Yii are both open source tools. It seems that Yii with 4.86K GitHub stars and 2.22K forks on GitHub has more adoption than Yesod with 2.11K GitHub stars and 329 GitHub forks.
According to the StackShare community, Yii has a broader approval, being mentioned in 58 company stacks & 32 developers stacks; compared to Yesod, which is listed in 5 company stacks and 5 developer stacks.