Vintage Software Copyright

[Tothwolf]

On Fri, 21 Aug 2015, Chuck Guzis wrote:
> On 08/21/2015 10:11 AM, Rod Smallwood wrote:
>
>> Yes OK and "very long"  would be?
>
> It varies by country.  In the case of the USA, 95 years from publication 
> (for older works)  Other countries employ the author's life+x years 
> (usually 50 or 70)--live to a ripe old age and your copyright can run 
> for a very long time.
>
> In the USA, the rule of thumb is that you're generally safe with works 
> published before 1923, which, I imagine does not include much computer 
> software.

...and works published before 1964 which were either not registered with 
the US copyright office or which did not have their copyrights renewed. 
Those require some research to determine their status.