##Epub Format## Epub is actually a collection of files in ZIP format. You can create an epub without any specialize tool, for example taking a book's content from https://github.com/Gluejar/open_access_ebooks_ebook and running
zip -Xr9D The_Velveteen_Rabbit.epub mimetype * -x .DS_Store ##Pandoc## Pandoc is an easy to use command line tool to generate epubs, and a lot more markup formats such as LaTeX, Markdown, HTML5, Word docx and ODT are supported. Here is an example:
pandoc mybook.txt -o mybook.epub Read more about epub creation examples.
I have used it to conveniently generate epub from a Git repositories' documentation to easier reading.
##Sigil## A GUI alternative is Sigil, with the benefit of in-place editors as well as extensive styling tools.
##Online Epub Generators## If you cannot/do not want to install applications, there are online tools that can generate epubs, such as http://ebook.online-convert.com/convert-to-epub
