diff --git a/README.md b/README.md
index 1f385700..7143f56e 100644
--- a/README.md
+++ b/README.md
@@ -583,6 +583,8 @@ _Personal e-book management software._
   - [Calibre Web](https://github.com/janeczku/calibre-web) - Web app providing a clean interface for browsing, reading and downloading eBooks using an existing Calibre database. ([Source Code](https://github.com/janeczku/calibre-web)) `GPL-3.0` `Python`
   - [COPS](https://blog.slucas.fr/en/oss/calibre-opds-php-server) - Lightweight e-book server alternative to Calibre content server or [Calibre2OPDS](https://calibre2opds.com/2011/11/03/new-site-for-calibre2opds/). ([Demo](http://cops-demo.slucas.fr/index.php), [Source Code](https://github.com/seblucas/cops)) `GPL-2.0` `PHP`
 
+- [Polar Bookshelf](https://getpolarized.io/) - Polar is a personal knowledge repository for PDF and web content supporting incremental reading and document annotation ([Source Code](https://github.com/burtonator/polar-bookshelf)). `GPL` `JS` 
+
 _Enterprise-class library management software._
 
 - [Evergreen](https://evergreen-ils.org) - Highly-scalable software for libraries that helps library patrons find library materials, and helps libraries manage, catalog, and circulate those materials. ([Source Code](https://github.com/evergreen-library-system/Evergreen)) `GPL-2.0` `PL/pgSQL`