Indeed, as far as IP is concerned, the following rule governs.
[...] your deduction for a donation of a patent or other intellectual property is its FMV, minus any gain you would have realized if you had sold the property at its FMV on the date of the gift. Generally, this means your deduction is the lesser of the property's FMV or its basis. For details, see Publication 526. [...]
"The basis of an intangible asset is usually the cost to buy or create it."
They don't mention software specifically, but they say that for patents and copyrights you can only include costs you actually paid for, and you specifically may not include the value of your own time spent inventing or authoring.
[...] your deduction for a donation of a patent or other intellectual property is its FMV, minus any gain you would have realized if you had sold the property at its FMV on the date of the gift. Generally, this means your deduction is the lesser of the property's FMV or its basis. For details, see Publication 526. [...]
https://www.irs.gov/publications/p561/ar02.html
However it's not clear to me that the basis is zero for IP. Can you clarify with citations?