At the time of this revision (2016) the latest available version of the Java Runtime Environment (jre)) from Oracle Corporation (which acquired Sun Microsystems Inc in 2010) is referred to as Java SE 8 Update 111 or jre1.8.0_111 or just jre8. Oracle no longer provides updates to jre7 or earlier versions. Various Unravel program updates have occurred over time. While it is probably good practice to keep up to date with the latest version, the developer has tried to maximize backwards compatibility. The Unravel program can be run on any jre7 or jre8 version.
The jre is also available in 32-bit and 64-bit versions. A special native dll (dynamically-loaded library) file is available to Windows users for improved timer resolution when running the Unravel program. Both 32 and 64-bit libraries are available for use when running a 32-bit or a 64-bit jre respectively. These native libraries are named HiResTimer32.dll and HiResTimer64.dll. For improved backwards compatibility, HiResTimer32.dll was created using an early C++ compiler version. With that version the only dependent is the Windows KERNEL32.dll. The Visual Studio 12.0 C++ compiler was used to create HiResTimer64.dll and that requires Windows KERNEL32.dll and MSVCR120.dll dependents. Unless users running a 64.bit jre have access to MSVCR120.dll, the high resolution timer will fail to load. That dll needs to be located in c:\Program Files\Java\jre?\bin\ or c:\System32\ (not c:\SysWOW64\ which is for 32-bit!). As of Jan 2014 the earlier MSVCR100.dll was being dispatched with the jre. Users can obtain the 64-bit version of MSVCR120.dll from the web and place it in either of the above-mentioned locations. Unavailability of the high resolution timer is not a program-stopper. If the high resolution timer cannot be loaded for any reason the standard timer will be used (as would always be the case for users running the program on a non-Windows platform).
Byte-code (class files) for the Unravel program was created using development software (Java Development Kit jdk1.7) provided by Oracle Corporation. The Unravel program class files developed with this Kit will run successfully on either jre7 or jre8. Extensive use was made of the Swing package. The Unravel program can be successfully compiled using later versions of the Kit.