Thanks to everyone who has contributed pull requests and issues.
- The existing Emacs Scheme mode and Inferior Scheme mode.
- The source code for for Quack by Neil Van Dyke provided a model for many of the scheme-indent-function settings, smart paren closing, and pretty lambda.
- The source code for Geiser by Jose A. Ortega Ruiz helped me understand how to support completions and especially company-mode. In addition, I was able to make heavy use of a pull request to display images in the REPL.