- Set `Cookie.SameSite` to `Lax` when subdomains sessions share is enabled[*](https://github.com/kataras/iris/commit/6bbdd3db9139f9038641ce6f00f7b4bab6e62550)
- Add and update all [experimental handlers](https://github.com/kataras/iris/tree/master/_examples/experimental-handlers)
- New `XMLMap` function which wraps a `map[string]interface{}` and converts it to a valid xml content to render through `Context.XML` method
- Add new `ProblemOptions.XML` and `RenderXML` fields to render the `Problem` as XML(application/problem+xml) instead of JSON("application/problem+json) and enrich the `Negotiate` to easily accept the `application/problem+xml` mime.
- Add `ProblemOptions` with `RetryAfter` as requested at: https://github.com/kataras/iris/issues/1335#issuecomment-521330994.
- Add `iris.JSON` alias for `context#JSON` options type.
[Example](https://github.com/kataras/iris/blob/45d7c6fedb5adaef22b9730592255f7bb375e809/_examples/routing/http-errors/main.go#L85) and [wikis](https://github.com/kataras/iris/wiki/Routing-error-handlers#the-problem-type) updated.
Allow [handle more than one route with the same paths and parameter types but different macro validation functions](https://github.com/kataras/iris/issues/1058#issuecomment-521110639).
- Fixes [Poor performance of session.UpdateExpiration on 200 thousands+ keys with new radix lib](https://github.com/kataras/iris/issues/1328) by introducing the `sessions.Config.Driver` configuration field which defaults to `Redigo()` but can be set to `Radix()` too, future additions are welcomed.