What IEO is you can read here: https://www.coinstaker.com/initial-exchange-offering-ieo/; https://www.initialcoinlist.com/what-is-an-initial-exchange-offering-ieo/.

Today many people say that IEO is an “evolution of ICO” and predict a great future for it (see: https://bitcointalk.org/index.php?topic=5119748.0;all).

At the same time I couldn’t find a list of platforms organizing IEO today, so I decided to compile it myself and post it on BTT.

NB: check this list before you participate in IEO - https://www.blockchaintransparency.org/trading-advisory-list.

Active platforms:
1. Binance Launchpad (https://launchpad.binance.com/). The first IEO-platform. Next IEO, Celer, starts today.
2. Bittrex (https://international.bittrex.com/). The first and only IEO was cancelled (https://cryptonews.com/news/bittrex-suddenly-cancels-its-first-ieo-3528.htm/).
3. Idax (https://www.idax.pro/#/foundation/index). Next IEO, ZeroBank, starts at 26th March.
4. Exmarkets (https://exmarkets.com/launchpad). More than five active IEO’s.
5. Probit (https://www.probit.com/en-us/ieo). Three active IEO’s.
6. Latoken (https://latoken.com/). A lot of active IEO’s.
7. Coineal (https://www.coineal.com/ieo.html#en_US). Thre active IEO’s.
8. Below you will see the list of platforms, on which MenaPay, one of the projects I’ve translated (https://bitcointalk.org/index.php?topic=5055912.new#new), is holding it’s IEO. I don’t know anything about these platforms so please reply here if you have anything to share about them. Also I’m not quite sure that these platforms are fully IEO platforms, not just a place for selling tokens:
- https://sistemkoin.com
- https://chainex.io/
- https://www.icrypex.com/
- https://www.coinegg.com/
- https://www.finexbox.com/
- https://www.klascoin.com/
- https://abcc.com
- https://www.dcoin.com/
- https://60.com
9. One of BTT users offers his services in organizing IEO and he points to a rather large list of exchanges conducting IEO (https://bitcointalk.org/index.php?topic=5120875.0;all): I couldn’t find any confirmations regarding these exchanges.
10. EOSex - https://eosex.com/#/
11. ZB - https://web.zb.com/i/blog?item=684
12. ZBG - https://www.zbg.com/launchpadList
13. BW - https://www.bw.com/ieoVeracity
14. EXMO - https://exmo.com/en/news_view?id=2641
15. CoinBene - https://www.thedailychain.com/blog/komodo-backed-project-redfox-labs-to-run-ieo-on-coinbene/
16. Cobinhood - https://cobinhood.com/ico-services
17. BGOGO - https://bgogohelp.zendesk.com/hc/en-us/articles/360025351512-Bgogo-Apollo-Launchpad-Premium-Token-Listing-Channel-Launches-ARM
18. KuCoin Spotlight (https://www.kucoin.com/news/en-tutorial-for-participating-in-the-token-sale-of-spotlight-projects/).
19. Huobi Prime (https://cryptopotato.com/huobi-prime-the-beginners-guide-how-to-invest-in-token-sales/).

Upcoming platforms:
1. Ataix (https://ataix.com/ieo).
2. Okex ( https://www.chepicap.com/en/news/8147/okex-to-launch-platform-similar-to-binance-launchpad-ok-jumpstart-soon.html).
3. gate.io - https://cryptor.net/news/birzhi-kriptovalyut-gateio-i-bibox-zayavili-plany-na-otkrytie-servisov-ieo-3433
4. Bibox - https://cryptor.net/news/birzhi-kriptovalyut-gateio-i-bibox-zayavili-plany-na-otkrytie-servisov-ieo-3433
5. Drive - https://bitcoinexchangeguide.com/drive-market-crypto-exchange-plans-for-ieo-native-token-sale-and-listing-as-a-service-launch/

The list will be updated. Waiting for your corrections, comments and additions.
Updated 04.04.2019.