Onno is commercial software. You can buy Onno here:
Buy Single Processor Version only (24,95€)
Buy Multi Processor Version (Deep Onno) (44,95€)
Purchase and use of the software is subject to the terms and conditions of share-it (shown in the ordering process) and therefore by Onno's license agreement.
At the end of the ordering process, two download links will be shown. One is for the engine, the other one is for your license file. You have to download both.
In addition you will immediately receive an automatically generated email with the two download links. (This email also contains the license file as attachment. That is redundant: It is the same file that can be downloaded.) If you do not receive an email, please check your spam filter.
Please install the license file in the same directory where the engine is located, i.e. deep-onno-1-2-70-w32.exe or similar according actual version. See installation for details.
Please keep your order number. It will be used as password in the download area. I recommend to save the mail from share-it.
The number of cores used by the multi processor version is adjustable. So the multi processor version can also run in single processor mode.
The download contains two versions of Onno: The 32 bit Windows version and the 64 bit Windows version. The 32 bit version runs on 64 bit machines and 64 bit Windows, but not the other way round. You select the version during the installation. The 64 bit version computes about 50% more positions in the same time and thus is stronger.
In case you are using Linux: There are good chances to run the 32 bit version with newer versions of Wine. An experimental native 64 bit Linux version is available on the download page.
The Windows 32 bit version was successfully tested on the following systems:
It does not run with old versions of Wine (0.9.2 tested).
The Windows 64 bit version was successfully tested on the following systems:
The Windows 64 bit version does not run on 32 bit Windows systems. It does not run under Linux with Wine, even if it is 64 bit Linux.
This is an experimental version. It is not contained in the distribution, but available on the download page. I hope it runs on any x64 Linux with GLIBC 2.3.5 or above.
To make use of the multi processor feature, you must have a multi core and/or multi processor computer of course.
Multi core computers are standard since approx. 2006. If in doubt if your computer has multiple cores, check its manual or enter your processor name in Google.
The multi processor version also runs on single core single processor computers, but isn't any faster than the single processor version then.
Onno requires about 3 MB on the hard disk and – with default hash size – uses about 20 MB of RAM when run. This means that if you have sufficient resources to run any of above Windows versions, you can almost certainly run Onno.
As described on the installation page, you almost certainly want a Chess GUI to run Onno. Free Chess GUIs are available.
This website is also the documentation of Onno. An offline version is contained in the download.