It looks like there were two stages to unbundling. The first was to add a new, better, unbundled compiler, and the second was to remove the base one. These seem to have taken place in 1990 and 1992, respective.

Here's a press release dated April 18, 1989: http://simson.net/ref/free_software/compiler_clips.pdf

> Sun Offers New Unbundled C Compiler

> In addition, Sun introduced a new product, Sun C 1.0 -- its first compiler sold separately from SunOS ... A version of the C compiler will continue to be bundled and supported with SunOS but feature enhancements will be made to to the unbundled version only.

Thus, it can't be 1987.

I based the 1990 date because of discussions like http://tech-insider.org/free-software/research/1990/1002.htm...:

> Thank you for raising the issue of the unbundling of the Sun C compiler (SunExpert, June, p. 8).

Based on that 1989 press release, it may be the first unbundled compiler was in 1989, but https://blogs.oracle.com/tatkar/entry/studio_release_names_f... says that 1990 was the year of the "First unbundled rel (from OS)".

Then for the second stage, according to Sun Technical Bulletin July 1992 ftp://ftp.math.ethz.ch/hg/pub/doc/stb/stbjul92.ps :

> Sun does not plan to “bundle” any compiler with the Solaris 2.0 operating system. The C compiler, which has traditionally been included as part of the Sun operating system, will be sold as a separate unbundled product.

That Wikipedia page says Solaris 2 came out on June 1992, not 1991 as you wrote.

Digging around some more, http://www.xemacs.org/Documentation/21.5/html/internals_3.ht... says:

> In 1994, Sun and Lucid agreed to rename Lucid Emacs to XEmacs (a name not favorable to either company); the first release called XEmacs was version 19.11. In June 1994, Lucid folded and Jamie quit to work for the newly formed Mosaic Communications Corp.,

The first version named XEmacs was in September 13, 1994, so still a couple of years after the C compiler was fully unbundled.

My three points remain correct, with the replacement of "1991", "1992", and "1993" in the place of "1990."

It is probably no coincidence that this was around the time ANSI C became a standard.

I've been trying, but I don't see the connection.

At the time they sold several other compilers. "C, C++, FORTRAN and Pascal are priced at U.S. $2,000 quantity one and Modula-2 at U.S. $2,200 quantity one" says http://ftp.lanet.lv/ftp/sun-info/sunflash/1990/Apr/16.13.com... .

C++ wasn't a standard, but it was unbundled. FORTRAN was a standard, and it was also unbundled. How does being ANSI C affect things?

The point being that ANSI C compliance required compiler changes.

How does that affect anything? Unbundling doesn't depend on changing the compiler. I don't see how the business model is affected by ANSI standardization. How would things have been different if C were standardized in 1984 instead?

It may be that vendors uses it as an opportunity to unbundle (eg HP-UX).

I don't understand how it makes a difference. Unbundling is a sales strategy. They could have unbundled even without changing the compiler at all.

In any case, the literature I read (see earlier links) included discussion about improved optimizations, so even without ANSI there was a differentiation between the new unbundled compiler and the old bundled one.

Why do you think it's anything more than a coincidence?