Eventual Source and Scheduled Licensing

In business, timing is everything. A few months' lead developing and commercializing a product can mean the difference between commercial success and failure. For some commercial licensees , obtaining access to the source code now rather than eventually may justify paying for those license rights.

This business reality has encouraged companies to create licensing strategies that generate revenue from customers willing to pay extra for additional lead time to develop their products.

Artifex Software, the distributor of Ghostscript, uses such a scheduled licensing model. Initially new versions of Ghostscript are not fully open source, but at a later time they become open source under the GPL.

Ghostscript is intended to be embedded into printers to support industry-standard page description languages like PostScript and PDF. The lead time to introduce enhanced printers is short and the competition among printer vendors is fierce. Some of Artifex Software's customers seek a marketing advantage by getting new versions of Ghostscript early.

New versions of Ghostscript are distributed initially under the Aladdin Free Public License. They are also distributed under Artifex Software's commercial licenses.

Despite its confusing name , the Aladdin Free Public License is not an open source license. It prohibits commercial distribution of Ghostscript or of products containing Ghostscript. Commercial distribution of Ghostscript requires an Artifex commercial license ”for which there is a royalty.

Peter Deutsch, the author of Ghostscript and the first practitioner of this scheduled licensing model by which commercial time-advantages can be paid for, describes the Aladdin Free Public License this way:

This License is not an Open Source license: among other things, it places restrictions on distribution of the Program, specifically including sale of the Program. While Aladdin Enterprises respects and supports the philosophy of the Open Source Definition, and shares the desire of the GNU project to keep licensed software freely redistributable in both source and object form, we feel that Open Source licenses unfairly prevent developers of useful software from being compensated proportionately when others profit financially from their work. This License attempts to ensure that those who receive, redistribute, and contribute to the licensed Program according to the Open Source and Free Software philosophies have the right to do so, while retaining for the developer(s) of the Program the power to make those who use the Program to enhance the value of commercial products pay for the privilege of doing so. (Aladdin Free Public License.)

The Aladdin Free Public License imposes certain specific restrictions on distribution. Among other things, it prohibits the commercial distribution of Ghostscript software if any payment is made. The license describes (in section 2) some types of distribution that are not allowed:

• When payment is made directly for a copy of the Program.

• When payment is indirect, as for a service related to the Program.

• When payment is made for a product or service that includes a copy of the Program "without charge."

In many other respects, the Aladdin Free Public License reads like the GPL. Like the GPL it allows examination of the source code and the creation and distribution of derivative works. It even contains a reciprocity condition:

You must cause the Work to be licensed as a whole and at no charge to all third parties under the terms of this License. (Aladdin Free Public License section 2[c][ii].)

Artifex Software, the commercial distributor of Ghostscript, simultaneously sells licenses to new versions of the program under commercial licenses. Those licenses allow customers to embed the most recent versions of Ghostscript into their printers. They also allow commercial licensees to use the source code in any way they wish, and they do not impose reciprocity obligations for derivative works.

Approximately one year after a version of Ghostscript is made available under the Aladdin Free Public License and its commercial licenses, Artifex Software re-releases that version under the GPL, at which point the software becomes truly open source.

The incentives for Artifex customers to buy commercial licenses are obvious. They can use the very latest versions of the software, with all the latest features. They can contract for the support of Artifex Software engineers to help them create their own products and derivative works. They can purchase warranties.

That extra time and those added-value services make scheduled licensing succeed as an open source business model. But such software isn't initially open source, and its licensors promise only that it eventually will be.