Tools: Archiving

ArchiveBox (free)
An open-source app to self-host your own private web archive. It saves HTML, JS, media files, PDFs, images and more as local, static, browsable HTML clones. You can even archive your entire browser history.

Archivy (free)
A self-hostable knowledge repository that allows you to preserve content in your own personal, searchable and extensible wiki.

Pinboard (free and paid options)
A bookmarking service. Paid; archiving (document repository) is a separate yearly fee.

Pocket (free and paid options)
A paid account allows you to build a permanent library of everything you’ve saved, complete with highlighting.

Polar (free and paid options)
Tagging, annotating, highlighting, keeping track of your reading progress for for web pages, textbooks, and PDFs; includes a document repository which saves all content (including webpages) into your account so even if the website goes down, you can still access its data from your Polar account.

Readwise (free and paid options)
Sync your highlights from Kindle, Instapaper, Pocket, iBooks, and more.

Zotero (free)
Collects documents into a document repository, organizes the documents any way you want, creates citations and bibliographies, and lets you share your sources for collaboration.