(Hacked together from a few Reddit comments. Pardon disjointedness.)
Corel LinuxOS was a great distro. I reviewed it at the time.
It was the first serious big-backer effort to make Debian user-friendly and to make a Linux distro that could rival Windows NT 4 as a credible business desktop OS.
It has a custom remix of KDE -- I think KDE 2 -- heavily rewritten to make it more like WinXP. So they looked at Konqueror and discarded it as a bad job (overcomplex, trying to do too many different things... as KDE itself eventually decided too).
It had its own file manager, very like Windows Explorer. A real pleasure to work with. It even browsed Windows networks, better than anything can today.
IMHO, having used KDE since version 1, it was the best version of KDE ever and the only one I liked using. (2nd place: Red Hat Linux' Bluecurve edition in RH 9, before the Fedora/RHEL split, but that was just a really good theme and replacement of all the KDE apps with best-of-breed alternatives, which usually meant Gtk apps.)
I think Corel defaulted to Netscape Communicator as its web browser & email client -- Firefox didn't exist yet.
It was the first Linux ever to have display setup and adjustment using a graphical tool. You could just pick a colour depth from a drop-down, and drag a slider to adjust screen res. Just like Windows. This was world-beating stuff in the late 1990s -- nobody had ever seen anything like it on any Unix before. (Except maybe NeXTstep on its proprietary hardware. Which didn't do colour at all in the first versions.)
And of course it had WordPerfect, too. Remember this is before StarOffice (later OpenOffice later LibreOffice) was acquired by Sun and made freeware and later FOSS.
WordPerfect started out on Data General minicomputers in the 1970s. It was ported to everything early on. There were versions for the Atari ST, Amiga, OS/2 and classic MacOS as well as for MS-DOS.
The original edition was text-based and famed not only for its speed and very useful "reveal codes" function, which split the window into 2 showing editable markup in the bottom half, but also its very rich printer support.
In the era of text-based OSes, pre-GUI, it was common for apps to have to provide their own printer drivers. The OS maybe managed spooling but nothing more. No drivers. If you wanted bold or underline, you had to write all your own drivers.
WordPerfect did this better than anyone. It supported just about every printer in the world and did it better than anyone.
This early text-mode WordPerfect also ran on text-based Unix. I had a customer who wanted it on SCO Xenix 386. I installed it. It worked and the printer support was great, but fought for control with SCO's spooler. I had to edit SCO's "printer drivers" (really just shell scripts with minimal start/stop/set paper size control) in order to get it working.
The result was not great. In the end the customer switched users who needed wordprocessing from terminals to PCs running local copies of WP, and a terminal emulator for talking to the SCO host.
(SCO did not include networking -- it was an expensive optional extra on an expensive OS. X.11 was another extra. A C compiler was another.)
So WP always ran on Unix, for about 40 years, from before Linux was invented.
The first full-GUI WYSIWYG version, I think, was on OS/2 2. That was later ported to Windows 3 (and wasn't very good at first).
That's the version that they ported to Linux, version 8 of a full native rich Unix app, but an old Unix app with an old design, probably originating on SCO and running on various 1980s proprietary non-x86 Unixes, such as AIX, Solaris, etc.
I used it and liked it but it was a bit clunky. Printer support was good, though, which was a weak point on Linux back then.
So when Corel did a Linux distro, a selling point was the inclusion of WP 8.
There were 3 separate versions of WordPerfect on Unix.
#1 -- the original text-based version, no GUI, for proprietary Unixes with no GUI, such as SCO Xenix.
#2 -- the later graphical version, derived in part from the OS/2 and Windows 3 codebase, which was bundled in Corel LinuxOS. This was WordPerfect for Linux version 8, and it was a full native Linux app.
#3 WordPerfect Office
So about #3...
Corel got really into Linux around the end of the 1990s. It ported graphical WYSIWYG WordPerfect, it did its own distro, and it did its own ARM-based hardware, the Netwinder.
But there was no Linux office suite yet. WP 8 was the first credible commercial wordprocessor for the OS yet.
So Corel, flushed with confidence, and having now acquired WordPerfect Corp and part of Borland (for the Paradox database and Quattro Pro spreadsheet) and having its own Windows office suite, decided to port the whole thing to Linux.
But only WordPerfect was portable, cross-platform code. The other apps (Paradox, Quattro, Impress (presentations), InfoCentral (PIM) etc.) were Windows-only.
So it used WINE, specifically winelib. This was a related project to WINE but instead of letting you run Windows binaries, winelib lets you port Windows apps to Linux by providing Windows-compatible APIs to link to.
The result is a native Linux binary, although often called WHATEVER.EXE, which installs and runs natively -- but displays everything by calling winelib functions which translate Windows API calls to Linux ones.
That's how WordPerfect Office for Linux was written. Custom, tailored versions of the apps, with stuff that was totally Windows-specific removed, and features adjusted to work with winelib. But still, not a true native Linux app -- a suite of big complex Windows apps ported to Linux via WINE, and so dependent on WINE. And this is 20y ago and WINE wasn't very mature yet.
It worked and it was the first native (ish) Linux productivity suite, but it was buggy and unstable.
But then Corel did a fateful deal with the enemy. With Microsoft.
To improve adoption of WordPerfect Office on Windows, some gullible Corel boss was persuaded that what WPO needed was to be more compatible with MS Office. And the way to do that was to license the Office look and feel, i.e. the custom menus and toolbars, and the Visual BASIC for Applications macro language.
(Aside: you should realise that VBA was bolted on to MS Office when Office was quite mature. Word had its own macro language, WordBasic. Excel had its own too, similar to Lotus 1-2-3 in-cell macros. These were ripped out and replaced with VBA. For a while Excel could run _both_. That's what Corel did too... only it didn't even own the code it replaced its macro languages with.)
Corel licensed VBA and the look and feel and bolted them onto WPO for Windows. It paid a lot. Tens of millions, US.
But Microsoft insisted that Corel kill off all its Linux work as a result.
And Corel bought it. So it killed WPO for Linux... and CorelDraw for Linux and its other Linux apps. It killed WordPerfect for Linux, the native port. It killed the NetWinder and it killed LinuxOS. A lot of people lost their jobs.
The NetWinder and LinuxOS got sold off.
Corel LinuxOS became Xandros, also a damned good distro, but with no WordPerfect and no big-company backing. There were 2 more releases then it died.
The NetWinder sold some units as a thin client and then died.
But Microsoft had eliminated the only serious rival desktop OS that existed and it got paid money to do so!
And all this did Corel little good, because Microsoft just switched out the look-and-feel in the next version of Office anyway. If you install all the versions next to each other, they all look different.
Office 4 for Windows 3 just looked like a native Windows 3 app.
Office 95 had custom skins and title bars and buttons, so it looked more like a Win95 app with weird title bars.
Office 97 dropped the fancy styled title bars but made buttons squarer and so on, brought in tooltips everywhere, and switched all the file formats so you had to upgrade.
Office 2000 brought in the horrible self-customising menus, the edges of toolbar buttons disappeared except when hovered over... And Corel didn't get it because the licensing was not forward-looking, it was for one version only.
Office XP had "intellisense" and an unhelpful Help box and wizards everywhere instead of dialog boxes.
Office 2003 had more of the same, horrible shaded gradients in the toolbars and menus.
Office 2007 ditched menus for ribbons and I stopped using it.
Corel LinuxOS was great, ahead of its time, but Microsoft killed it.