Okular

It is a very good alternative to Sumatra, and evidently its greatest advantage over this are the PDF annotations.
Some functions that I use a lot in Sumatra and that are NOT in Okular are:

• Open multiple files in tabs, in a single window. Okular works Office style, it will open one window per file, which is not practical.

• File history, and possibility to reopen them ALL automatically when starting the program.

• In the Windows version, Okular occupies more than 400 Mb, while Sumatra less than 20 Mb.

Finally, a very commented problem is the lack of a "standard" installer in Windows. I had the same problem, and after abandoning all this and trying MuPDF (quite limited) I gave it a last chance, and it turns out that IF THERE IS an installer that is very hidden...the link is below.

There you will find the typical *exe, and also a 7z compressed that will make the portable version (the executable is in the bin folder).
If you navigate within that web, you will also find the "Nightly" versions of Okular, and also other applications of the KDE community

Mensaje Original:

Es una muy buena alternativa a Sumatra, y evidentemente su mayor ventaja respecto a esta son las anotaciones en PDF.
Algunas funciones que uso bastante en Sumatra y que NO están en Okular son:

• Abrir múltiples archivos en pestañas, en una sola ventana. Okular trabaja al estilo Office, se abrirá una ventana por archivo, lo cual no es práctico.

• Historial de archivos, y posibilidad de reabrirlos TODOS automaticamente al iniciar el programa.

• En la version de Windows, Okular ocupa mas de 400 Mb, en cambio Sumatra menos de 20 Mb.

Finalmente, un problema bastante comentado es la falta de un instalador "estándar" en Windows. Tuve el mismo problema, y tras abandonar todo esto y probar MuPDF (bastante limitado) le di una última oportunidad, y resulta que SI EXISTE un instalador que esta muy oculto...lo encuentran en:

https://binary-factory.kde.org/view/Windows%2064-bit/job/Okular_Release_win64/

Alli encontraran el típico *exe, y tambien un comprimido 7z que hará las veces de versión portable (el ejecutable esta en la carpeta bin).
Si navegan dentro esa web, también encontrarán las versiones "Nightly" de Okular, y tambien otras aplicaciones de la comunidad KDE.

This is the only PDF (PDF only!) reader that satisfies me fully in all 3 dimensions: open source, functionality and speed. All the other readers that I tried have a shortfall in at least one of the 3 - Adobe Reader, Foxit Reader, Sumatra, DPF.js, STDU, Icecream ebook reader. I won't describe it in full, you'd better try it and see for yourself. I'll just mention my favourite functional features - cursor pointing to the active chapter in the contents tab, Trim margins option, filter field for all tabs - Contents, Thumbnails, Reviews, Bookmarks and a convenient hand tool switch (it's called Browse).
But keep in mind - it's good only for PDFs and only for reading. It's bad for reading epubs for example and can't edit files. Also its installation on Windows is hidden somewhy, but all you need to do is install KDE via KDE on Windows from Sourceforge. This installer incapsulates the programs including Okular.

[Edited by VPupkin, August 22]

You can left-click the document and drag it indefinitely up and down. You won't hit the screen-border and start grabbing it on top again. That enables quick navigation. I don't know any other reader that is able to do this. On top, Okular supports note-taking, drawing and highlighting.

Has all the features I require for light editing of a PDF, and is a great tool to read PDF documents

Remembers last time you left it. Runs superfast. Cross-platform.

Thumbnail view is a blessing. Just note when you re-open the last document, the thumbnail column will be unsynced until you go to the next/previous page.

From Debian 10 using i3wm.