but not for long - Mozilla may end support for Firefox 52.x ESR by the end of 2018 or early 2019.
as for Palemoon browser, XP support was removed in Palemoon version 27, last official version that supported XP was v26.5 but this version is not available anymore on their web site.
Browsers updated currently for XP:
New Moon: rtfreesoft.blogspot.com/search/label/browser
FireFox --> Pale Moon --> "Mypal" (XP SSE2) Best
FireFox --> Pale Moon --> "New Moon" (XP SSE2)
FireFox --> Pale Moon --> "New Moon SSE" (XP SSE) I have "Pentium III" and "AMD Athlon XP" working well.
FireFox --> Pale Moon --> "New Moon noSSE" (XP MMX)
Firefox 52.9.0 ESR will receive updates 52.9.x ESR until September 5, 2018.