EXE format means that the eBook is actually a PC executable. Basically the eBook includes the program to display it.
EXE is the extension assigned to mark executable files on Windows PC and some other systems. An EXE can be executed by tapping it in an explorer window or typed on the command line using a CLI if it is in the search path. You don't need to actually type the exe extension.
For an eBook it means the executable file is designed to display the eBook you want to read. Each executable is designed to display one book or one collection of books (all in the same file as the executable). If you want to read another book you would download another executable. Note that the executable may also save a side file that contains references to bookmarks and notes as well as the current progress.
While not actually using the EXE extension there is a program for the iPhone that creates eBooks that are executable. It is certainly possible to have programs for other platforms that behave like an EXE and provide eBook reading capability. Unix (Linux) apps and commands typically don't have any extension.
- Each file is its own book. There is no other program to load or find. Just click the file to read the book.
- You can send the file to a friend that owns a PC without needing to send them a program to read it or telling them to download one from somewhere.
- You have good control over how the eBook pages look.
- Fixed layout ePub books are good candidates for this kind of treatment.
There are some disadvantages with this format.
- Downloading exe files is always suspect in that they could really be a virus.
- Files are bigger than they need to be since every book has a copy of the reading program embedded in it.
- Typically these eBooks can only be read on a Windows PC (or on the OS that was used to create them).
- If the EXE comes from a different program it can have a different user interface which can be confusing.
 Self extracting zip
An exe file can also be a self extracting ZIP file. It this case it is a container format and can contain any form of data. Often the file contains a pointer that will automatically start a program that is inside the zip file itself. This is often used for install programs where the downloaded exe file will be clicked by the user the following actions follows:
- The self extracting zip file executes and extracts the files inside, usually to a Temp folder. Occasionally a windows prompt will appear for the user to determine the folder.
- Once the file contents is extracted the designated program will be started. This program is generally inside the file itself. Often this program is an install program but it could also be the eBook reading program or may call such a program.
- The program executes and is under control of the user. If it is an eBook program you will see the eBook and can begin reading and using the features of the program.
- When you exit the program it will generally erase all of the files that were extracted to the Temp folder. However, the running program cannot be erase itself so a small remnant will be left. Good programming practice would erase earlier copies if the program is run a second time but some programs do not do this.
Note that this file is still a standard zip file with the exe program pre-pended to the file. A zip extraction program can be used manually to inspect the contents or extract the contents.
The disadvantage of using this technique for eBook reading is the startup delay while the files are being extracted.
 Programs that can create EXE eBook files
- EBooksWriter can create EXE standalone files as one option.
- eBook Edit Pro creates an EXE file from an HTML file.
- Kotobee#Author can make apps for Android, iOS, Windows phone, Windows, Mac OS X, and Chromebook.
- HTML to EXE convert HTML to EXE, will also do PDF and ePub, You can decompile CHM to make standalone help files.
- eBook app builder - online fee based system. Builds apps for iOS and Android
- app builder - AppInstitute is an easy to use DIY eBook App Builder for small businesses