
: Re: Are there good ebook management tools available for free? I have a collection of e-books and I am looking for a way to manage it from my operating system. What are the programs to manage
Calibre
It is the leading ebook management tool. However, you should be aware when you do add a title into Calibre it will embed a bookmark file in the META-INF folder and will modify your .opf file. Other than that it is avaiable for all environments:
Calibre for Windows; 64-bit
Calibre for Mac
Linux; How to install on Ubunutu:
sudo add-apt-repository ppa:n-muench/calibre
sudo apt-get update
sudo apt-get install calibre
Portability on a thumb drive
Adobe Digital Editions
Free and from Adobe. Be advised there has been some issues lately in viewing DRM .epub 3.0 ebooks and the fonts not rendering correctly. This is a bug that was introduced a few months ago on the update but no word yet on when the issue will be addressed. Download page for Adobe Digital Editions. You can install ADE on Ubuntu but you will need Wine. Good article read: "Howto install Adobe Digital Editions on Ubuntu 12.04 and use it with an e-book reader"
BookONO
A management tool I haven't tested or used but they are trying to compete with Calibre so it could be a worthy alternative: BookONO E-book Manager
Adobe PDF Reader
You mention ebooks but not what type. So just throwing Adobe PDF Reader for web .pdfs. Good write up over at AskUbuntu on installing adobe PDF reader on Ubuntu: "How do I install Adobe Acrobat Reader?"
A few others I've heard but haven't used:
Delicious Library 3
Alfa Ebooks Manager
Moon+ Reader
All my books
Data Crow
Lucidor
After the added tag mac-os:
iBooks
KooBits
Scida
Free books android app tbrJar TBR JAR Read Free books online gutenberg
More posts by @Frank

: PDB is a container format for record databases in Palm OS, Garnet OS and Access Linux Platform. It's structure is similar to PRC resource databases. Barnes and Noble's converts epub to pdb

: EReader is a freeware program for viewing Palm Digital Media electronic books which use the pdb format used by many Palm applications. Versions are available for iPhone, Palm OS (not webOS),