@WuMing2
I don't know what you mean by "self hosting" (of what?), "integration with banks" and "free for all market" - maybe there is a misunderstanding of what #Taler is?
It is a collection of protocols for three parties: the customer/wallet, the exchange (payment service provider) and the merchant. It consists of all steps necessary for digital payments: initial funding, coin withdrawal, anonymous coin spending, coin deposit, refresh/getting change. The funding and the deposit steps both involve regular wire-transfers from/to bank accounts of the customer/merchant, respectively.
The software implementation #GNUTaler is free software, and anybody can download, alter and run it - all parts of it. The wallet is clearly self-hosted by the user; a merchant can host the Taler-merchant-backend component themself - or use the service provided by somebody who runs it for multiple merchants (taler-ops.ch f.e.).
The exchange component is a different story, though:
For event or local currencies (not fiat currencies), under certain rules depending on your local jurisdiction, you may be allowed to run an exchange legally for that (fake) currency, f.e. for an event or a local community. This would be "self-hosting" the exchange.
What you can not do legally, without having the necessary license, is "self-hosting" an exchange for, say, the Euro (€). This requires an e-money issuer license, that only some banks and some fintech companies have. This is why the GLS bank (Germany) and the Magnet bank (Hungary) are members in the #NGITaler consortium - to legally host the Taler exchanges for the Euro (in Germany) and the Forint (in Hungary).
Other jurisdictions have less tighter regulations, f.e. Swiss law allows to operate as e-money issuer for Swiss francs as long as the total sum in the system is below a threshold (and one is compliant with Anti-Money-Laundering (AML) requirements).
Did I address your question?