What are some alternatives?
When comparing Pearltrees and Raindrop.io, you can also consider the following products
Tagpacker - A free tool to quickly collect, organize, and share your favorite links.
Pocket - When you find something you want to view later, put it in Pocket.
Diigo - Diigo is a powerful research tool and a knowledge-sharing community
Pinboard - Pinboard is a personal archive for things you find online and don't want to forget.
Pinterest - Pinterest is a visual discovery tool that you can use to find ideas for all your projects and interests.
start.me - A Modern-day bookmark manager. A place for your favorites. A news feed (RSS) reader. A browser startpage. A portal for your team.