Bring your own copy
ENCORE projects contain no part of the original games: no code, no art, no sound or music, and no data — not even values copied out of the program itself. That is a rule in every repository, not a guideline, and it shapes how the ports are built.
What the projects read
Each port reads the game from your copy at run time — the CD itself, an image of it (.iso, or a raw .bin), or an installed folder, depending on the game. Several of them read the installer archives on the disc directly, so you never have to run a Windows setup program. Even the numbers and settings built into the original program are read from your copy of that program when the game starts, not compiled into the port.
Most projects support exactly one version of the original program, identified by its size and CRC-32, because a function-by-function port is a port of that one build. If your copy is a different version, the game says so at start-up, naming what it expected. Each game's page in the collection says which version to bring.
In the browser the same applies: you pick your disc or folder, the page checks it, and it is read locally — nothing is uploaded anywhere. The sites host only the engine.
Where to get the games
The disc you kept is the best answer. Second-hand copies of most of these games are easy to find. Where a game is sold today, buy it — from stores such as GOG, which sells old games without DRM and, through its Preservation Program, commits to keeping them working on modern systems. Each game page links to a GOG search for that title; whether a given game is available there, and in which version, changes over time, so check before you buy.
One exhibit is different: Babo Violent 2 was released by its authors under the GPL, data included, so openbv ships with its content.
What the projects never do
They never link to downloads of the games, never call a game "freeware" or "abandonware" without an official source saying so, and never commit screenshots, dumps or files derived from game data unless the project's own rules allow screenshots of the running port. See Wording in the guides, and the encore-data-hygiene agent skill.
Trademarks and copyrights in the original games belong to their owners. ENCORE projects are not affiliated with them.