⚠️ I am not responsible for the content of the links, it is not my content. I have only collected what's still around in the web (or archived). Use a translator if needed.

MobileFree ru as "the goto" forum/wiki
https://justdanpo.ru/data/projects/gsm/ (used to be justdanpo.cheb.ru/) and
https://justdanpo.ru/data/support/elfpack/ elfpack builds
http://setool.sonyericsson.org/
Wikipedia list of all SE accessories

https://www.omnius-server.com:9999/ https://www.kaijousuru.com:9999/
https://archives.omnius-server.com:9999/ https://archives.kaijousuru.com:9999/

https://www.akshayy.com/sonyericsson/index/
https://lpcwiki.miraheze.org/wiki/Sony_Ericsson
https://operationse.github.io/ from sharko and its Github

https://mobilefree.justdanpo.ru/ (also shortly under supertrubka.org, which was originally mobilefree.ru)
https://sony.yt/forum/294-tutorials/
https://www.esato.com/board/viewtopic.php?topic=189669
https://forum.se4ever.ru/
https://se-tuning.cz/
http://www.sonyericsson-world.com/
https://seclub.org/forum/topics/76/
https://www.faq4mobiles.de/foren/sony-ericsson.42/
https://www.topsony.com/forum/cmps_index.php

Note: All archive.org timestamps are rather randomly picked. Pages might not be usable anymore.
http://web.archive.org/web/20061128001225/http://developer.sonyericsson.com/site/global/docstools/java/p_java.jsp
https://web.archive.org/web/20101128102447/http://se-developers.net/index.php
https://web.archive.org/web/20120205064356/http://www.se-world.info/index.html
se-nse.net v5 forums
#note: play with timestamps for archive snapshots of se-nse.net
se-nse.net v6 forums
https://web.archive.org/web/20130827151905/http://forum.elfse.com/
https://web.archive.org/web/20120621233459/http://www.se-lifestyle.com/index.php
https://web.archive.org/web/20160625233809/https://forum.se-zone.ru/viewtopic.php?t=3925
https://web.archive.org/web/20111007085513/http://topse.ru/forum/
Developer-se.pl
https://web.archive.org/web/20110716043323/http://www.seusers.com/foro/forum.php
https://web.archive.org/web/20100609123842/http://www.c902.eu/
https://web.archive.org/web/20040610190507/http://mobile.box.sk/manufacturer.php3?newsprj=ericsson
https://web.archive.org/web/20060722063621/http://lasyk.net/ https://web.archive.org/web/20100507042749/http://seusdb.10001mb.com/index.php

https://www.iprotebe.cz/sony-ericsson-section1.html
iprotebe.cz files: https://drive.proton.me/urls/AQ1358PNAR#m27WWE7EV2XJ
https://firmware.center/firmware/Sony-Ericsson/
Dumbphone Repo: https://mega.nz/folder/2aoVnJJJ#ovZJG4cbvIOqLVEJBHrQSQ
https://mega.nz/folder/MtV0HIiB#68pyinmvk9UHpZB6gbF3yQ
TopSony files: https://drive.proton.me/urls/BDTEBARJGW#3fXzAPn6lS1O
[archive.org]https://archive.org/download/tems_20250222
DB3350 stuff: https://disk.yandex.ru/d/SOeLDFdbP1ZuUA
https://www.4shared.com/account/dir/tB2YurBu#dir=kseGk9Pi
https://www.4shared.com/folder/eI_ZJYC9
https://www.4shared.com/u/wCBqbkTu/adhitya_1978.html
unsorted files: https://mega.nz/file/E6pyCIbR#trOMFmCYJVuhcQgahQJGVhq3wGAZPJ43SLJKPoFXRBw
some version of Far manager: rather download somewhere else mega.nz link
Omnius for SE downloads: https://drive.google.com/file/d/1l_Sy5BYA7t_LNLIhh2Ej7JpYodKCw49N/view?usp=sharing

https://j2me-docs.narod.ru/ J2me SDK
https://github.com/MIDletPascal MIDletPascal / AMPAS IDE
https://github.com/hstsethi/awesome-j2me collection / list for J2me
https://github.com/hstsethi/j2me-preservation collection / preservation for J2me

List of J2me emulators
List of emulators on J2me

https://planet-surfeu.de/
http://dedomil.net/games/
https://mobile.phoneky.com/games/
https://www.mobygames.com/platform/j2me/
https://www.myabandonware.com/browse/platform/j2me/
https://bluemaxima.org/kahvibreak/
…
https://archive.org/details/j2me-archive-unified-2019-09
https://archive.org/details/mobiles24j2me and also search archive.org for j2me or jar games
…and many more

https://nikita36078.github.io/J2ME_Docs/ J2ME docs
https://docs.oracle.com/javame/developer/developer.html Oracle docs
http://j2megame.atw.hu/
https://billday.com/javame/ list of books
https://sourceforge.net/projects/isoj2me/ \\isometric engine https://j2me.fandom.com/wiki/Tutorials
https://www.wideskills.com/j2me-tutorial
https://bora.uib.no/bora-xmlui/handle/1956/1463 J2me programming MA thesis 2004 […] there are tons of J2me (game) programming tutorials out there, just search

https://vk.com/se_community
https://t.me/ModdingLikeIts2009
https://www.reddit.com/r/vintagemobilephones/comments/1e36wbe/new_owner_of_omnius_free_firmware_archives/
Kaijousuru on discord: https://kaijousuru.com/discord
Kaijousuru discord invite link: https://discord.gg/M64MVqeCBe

https://www.maxbhi.com
https://n-tel.eu/index.php?id_category=14&controller=category&id_lang=1 (Poland only)

FAR Manager and its plugins:
https://github.com/d4rkmen/PhoneFS

http://web.archive.org/web/20070219032816/http://www.davinciteam.com/index.php?page=manual-cablemod
T28 Service and Data Cable Conversion
https://vonkonow.com/using-a-sony-ericsson-dock-as-an-usb2serial-adapter/ DSS-20 as serial for T28 connector
T28 connector and info on lpcwiki
MW600 disassembly
- mod/solder MPS-Series speaker fastport to USB-A+3.5mm (✅ done) (or even USB-C with analog audio?)

C901 schematics
W995 schematics
C905 schematics
K800/K750 schematics

https://hackaday.io/project/7496-mmr-70-cheap-radio-module
https://hackaday.com/2014/11/12/2-fm-transmitter-for-rasberry-pi/ info summary with FMBerry
https://www.mikrocontroller.net/topic/252124
http://achilikin.blogspot.com/2013/06/sony-ericsson-mmr-70-transmitter-led.html
http://achilikin.blogspot.com/2014/06/sony-ericsson-mmr-70-modding-extreme.html
http://www.elektronik-labor.de/AVR/MMR70_2.html

https://www.mikrocontroller.net/topic/358873
http://tiny.systems/categorie/hardwareHacks/index.html

http://sonyericsson.org:64/ Youtube 2009 with its settings
http://146.59.80.3/ jar benchmarks
https://harshalkutkar.wordpress.com/2010/01/20/sony-ericsson-phone-modding-and-flashing-tutorial/
https://mtronicscell.blogspot.com/search/label/Sony%20Ericsson%20Flash%20Files + Guides

Info about which service cables with smartcards are still active.