WikiSuite is the most comprehensive and integrated Free/Libre/Open Source enterprise software suite ever developed, so you'd expect that it took a massive amount of work. But how much? As of 2019, WikiSuite's cost to develop is well over 50 million $USD.
Yes, really: If you tried to re-code WikiSuite using proprietary models. Below are the reports for various WikiSuite components generated by Black Duck Open Hub. Here is one example: https://www.openhub.net/p/tikiwiki/estimated_cost, and it has this note: "COCOMO is meant to include the design, specification drafting, reviewing and management overhead that goes along with producing quality software." More info:
Like Wikipedia, GNU/Linux and Firefox, WikiSuite is the result of massive collaboration.
Nope. Just the Linux Kernel would cost billions to redevelop
The WikiSuite-specific code (mostly ClearOS installers):
This is intentionally as small as possible since we focus on upstreaming code to the various Software Components
We won't count KVM as we consider it as part of GNU/Linux
In some cases, it's actually underestimated. COCOMO counts the number of lines of code. But a project like Tiki has been in active development for over 16 years, and there has been over 68 000 code commits. This battle-tested code costs more to develop than a younger application that would have the same number of lines of code.
As of 2019-02-04, Tiki is estimated at $14,744,047, and the latest revision is #68960, which represents about $214 per commit. Given the work that goes into software development, and since "COCOMO is meant to include the design, specification drafting, reviewing and management overhead that goes along with producing quality software.", it is clearly not overestimated. But that doesn't even count the 125 external dependencies. Think about it. Each dependency represents a distinct community / code base / bug tracker / etc.
There is tiny feature overlap / code duplication in WikiSuite because our philosophy is to avoid it as per Component criteria. While it's true that some of WikiSuite have apps or plugins, it's mostly a deployment mechanism, and there is no mess like explained at: http://pluginproblems.com/
That is true of all feature-rich software. But the economics don't make it feasible to build software just for your needs. Community Free / Libre / Open Source software will necessarily want to cater to a wider community and get more users and contributors.
Most of the software components are 10 to 15 years old so they are mature. Maintaining apps, even with the occasional revamps, is a tiny fraction of the effort of re-writing. And now, each of the has a community / ecosystem which uses and makes sure to maintain and develop.
Even if we exclude dependencies (which is debatable), and not count all the components, we can see that it's "well over 50 million $USD". This demonstrates the following: