Gashapon, gachapon, gacha gacha, ガチャガチャ — same machines, different spelling.
What’s out this month, and whether your favourite series ever got a set. Search in English — “Attack on Titan” finds 進撃の巨人.
They all name the same machine. The word is a noise — the gasha of the crank turning and the pon of the capsule dropping — so it was never spelled one way to begin with. Bandai registered ガシャポン (gashapon), ガチャポン (gachapon) and ガチャガチャ (gachagacha); Takara Tomy Arts registered ガチャ (gacha) for its own. Written in Latin letters it drifts further — gashappon, gachappon, gacha-gacha, gasha pon, and gashagasha, which is what this site is called.
The generic term, and the one the archive is organised around, is capsule toys — カプセルトイ. A few hundred yen, one turn of the handle, one capsule, contents at random. Every set here is listed under the name its maker printed on the box, which is why the names on this page are Japanese and the search takes English.