An OTT file is the basis for creating multiple documents with the same properties. These files contain various formatting information, such as margins, headers, footers, and fonts and margins, as well as macros. These macros may contain malicious code, so you should do a virus check before you run them.
The OTT format is part of the Open Document for Office Application Standard, also known as OpenDocument. Originally developed by Sun Microsystems and based on XML, the standard has been defined and developed by the Organization for the Advancement of Structured Information Standards (OASIS).
Most often resolving problems with opening OTT files is very simple. Just install an appropriate program that supports such files. All of the listed programs support OTT files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of OTT files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate OTT files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the OpenOffice.org Writer applications is not on the list, select "Browse" option in order to manually locate the directory where OpenOffice.org Writer has been installed.
Sometimes problems with opening OTT files may not lie with the application itself, but can arise due to other causes, such as: