There exists some technology which is a SilverBullet--if deployed, this technology would increase the productivity of programmers by an order of magnitude.
This technology is being suppressed, for various reasons, including:
By vendors of competing technologies, seeking to keep a DisruptiveTechnology (which would shrink the overall market size for their products) out of the hands of customers.
By vendors of competing/complementary technologies, seeking to maximize revenue by introducing the technology to the marketplace gradually (and thus requiring multiple upgrade cycles--the SergeiBubkaStrategy)
By the programming community, seeking to prevent the appearance of something that would make 90% (or whatever ratio seems appropriate) of programmers obsolete; thus resulting in massive unemployment and paycuts among programmers.
Sometimes, it is unspecified what the SilverBullet alledgedly is. Other times, a particular technology which is widely praised but a commercial failure (SmalltalkLanguage for instance) is claimed to be a SilverBullet, and its failure in the marketplace is ascribed to the SilverBulletConspiracy.
Most if not all allegations of the SilverBulletConspiracy don't hold water. Most proposed silver bullets have been found to be made of lead or other base metals (occasionally one may find a silver alloy); and in the days of OpenSource software it would be nigh impossible for any vendor to actively suppress any technology. (Even with patents; the patented SilverBullet would have to be described in the patent application; it couldn't be kept secret).
Is this a joke?
No... I've seen it suggested before. And not just in the SW industry; it's an oft-repeated canard that Detroit is capable of producing whiz-bang automobile engines that get 70MPG or whatever with no loss in performance, but is withholding such engine technology at the behest of Big Oil.
Sure, I've heard it applied to machinery (cars that run on water, washing machines that don't need detergent, etc) - but never to software. Can you give an example?