https://freeware.palmclub.nl/
http://www.mobyware.org/palm-os-software-download-all-1-date.html
https://archive.org/details/tucows?and[]=subject%3A%22palm+pilot%22
https://www.oldhandhelds.com/?dir=Palm%20Os/Games

http://users.ics.aalto.fi/praiko/palm/ (select freeware)
https://tinyapps.org/palm.html (small useful apps)
https://palmopensource.com/palmdb.php
https://mariomasta64.me/palm/
http://web.archive.org/web/20081021095630/http://www.freewarepalm.com/listall.shtml
ftp://89.109.35.231/soft/PALM%20SOFT/Games/ (dubious warezy place, but has simcity!)

sdk/rom archive https://drive.google.com/drive/u/0/folders/1kRspcGzHQhAhtPsF3Zr3iP0W574CgmDR

Rom Images http://mypalm.ru/html/emul-rom.shtml

Mega Archive https://mega.nz/#F!0R83jACK!Ba1v2vsS4x81emugSgohxA!AZkyARYI

SDK
http://web.archive.org/web/20141224205957/http://cdn.xenu.tk/pub/palm-archive/pub/programming/sdk/
https://github.com/jichu4n/palm-os-sdk
https://databug2210.blogspot.com/2017/12/appalm-clie-ux50.html (links to clie sdk archive files)
https://web.archive.org/web/*/http://www.jp.sonystyle.com/Clie-dev/file/* (ignore zips with text/html type)
https://web.archive.org/web/*/http://www.us.sonypdadev.com/file/* (ignore zips with text/html type)