title_body: Without ebook creation software, can I fix formatting issues on an epub? I have an epub copy of a book where all the lines are broken up wrong, and it ends up looking like really bad free form poetry. This makes the book really hard to read. Is there a way for me to fix this sort of problem on my own, without having some sort of software to make ebooks, or am I stuck just trying to find a version of this particular book without this problem?
upvoted_answer: Depending on what you mean by ebook creation software. You can always:
  
  
  Rename the epub to a zip (change the epub suffix of the filename to zip)
  Extract the zip file. 
  Manually edit the extracted HTML files with your favorite text editor - this assumes that you have an understanding of formatting with HTML
  Repackage the files/folder to zip again
  Rename the zip to epub again. (As user3019828 pointed out in a comment: you need to use a zipper that won't compress the mimetype file. For Windows, ePubPack is an option; for Mac, you can use ePub Zip.)
  
  
  The above steps does not involve any specific ebook creation software... But you should give a try to Calibre's heuristics fixing capabilities too. And Calibre also has a GUI to refine ebook contents...