vim-plug, written by Junegunn, is one of the most popular Vim plugin managers out there.

• Easy to set up: Single file. No boilerplate code required.
• Easy to use: Concise, intuitive syntax
• Super-fast parallel installation/update (with any of +job, +python, +python3, +ruby, or Neovim)
• Creates shallow clones to minimize disk space usage and download time
• On-demand loading for faster startup time
• Can review and rollback updates
• Branch/tag/commit support
• Post-update hooks
• Support for externally managed plugins

MIT License

Junegunn writes about vim-plug in his blog post Writing my own Vim plugin manager.