Usury is a major sin in Islam, what about the other religions?

Usury is the practice of making contracts for the lending or borrowing of money on unethical terms, or when it’s being borrowed unnecessarily. 

It is permissible to borrow money to purchase a home, where the borrower can reasonably pay off the debt. 

Under Christian principles, it is acceptable for interest to be paid on the amount borrowed, the borrower legally owns the property outright and should pay the lender any outstanding amount if the property needs to be disposed of before the loan has been repaid. 

Christian principles imply that lending money to pay for the necessities of life (eg. groceries) is unethical. However it is still permissible to use a line of credit such as a credit card or on a 'tab' when it’s inconvenient to carry physical cash (provided the purchaser could ordinarily afford those things if cash were convenient {debit cards don't count as lending they electronically transfer money the purchaser already has}).  If a person whom you know to be living in or close to poverty asks to borrow money for bread and milk, it’s better to give generously and just to give them those items (or the cash equivalent) and not demand or expect repayment. 

It's explicitly banned in the New Testament. That's where Islam got it. Christians have been ignoring this since the 17th century, because money.

Yes, usury or loan sharking is illegal in most countries.

Christianity also forbids it but this tends to be ignored, and Judaism isn't that keen either.

In Christianity it is best not to lend money out. Just give it to them.