How to: File Upload
* [attache](https://github.com/choonkeat/attache) - Standalone image and file server to decouple your app from file management concerns.
* [CarrierWave](https://github.com/carrierwaveuploader/carrierwave) - Classier solution for file uploads for Rails, Sinatra and other Ruby web frameworks.
* [DragonFly](https://github.com/markevans/dragonfly) - A Ruby gem for on-the-fly processing - suitable for image uploading in Rails, Sinatra and much more!.
* [PaperClip](https://github.com/thoughtbot/paperclip) - Easy file attachment management for ActiveRecord. Deprecated as of May 14, 2018.
* [rack-secure-upload](https://github.com/dtaniwaki/rack-secure-upload) - Upload files securely.
* [Refile](https://github.com/refile/refile) - A modern file upload library for Ruby applications, Refile is an attempt by CarrierWave's original author to fix the design mistakes and overengineering in CarrierWave.
* [Shrine](https://github.com/janko-m/shrine) - Toolkit for handling file uploads in Ruby.