The French , realistic about sex and about families and unions, created PACS in 1999. The acronym is from the French for 'civil agreement establishing solidarity'[Pacte Civil de Solidarite] This is an officially recognised state of union for both mixed and same sex couples.
It would not satisfy gays who want a true marriage equal in every legal respect to a heterosexual one but it goes a good way to addressing the problems of partners in such unions.
The couple sign a declaration that they wish to be regarded as a union and this is registered. It gives them much the same rights and responsibilities as the law provides for married couples; so they are each liable for domestic debts, they are deemed to own furniture jointly and so on. It goes beyond the trivial though. After three years together they have a common fiscal regime. If one, exceptionally, is not already covered by the social security system then he or she is included in the partner's coverage. So, once the couple are 'pacsed' they have a status in law between living together (which the French call 'concubinage'

) and marriage. Marriage in France is itself a civil matter; no religious ceremony gives any marital status in French law. Here the state is regulating and protecting those who have an antipathy to marriage or do not feel ready for it; that seems a natural progression from civil marriage law. The formalities for ending the arrangement are straightforward. It can be done unilaterally.
Provisions for inheritance were under consideration when the law was passed;I can't help on details of the progress though. French law has a basic rule (viz. 'Whatever the deceased has written his kids get first claim on the money; the widow gets what's left'

). How this is adapted for a case of a pair who did not have married status is not obvious.They cannot adopt children, not being married; what children they do have together are likely to gain under similar provisions; but beyond that would be speculation.
They cannot gain French citizenship through the arrangement; that really would be inviting difficulties

.
Would this simple provision go any way towards satisfying gay and hetrosexual couples (some of the latter suffer great injustice from not having that 'bit of paper' the marriage certificate ) and, more importantly, calming present opponents to gay 'marriages' in the US ?
( Didn't Vermont consider such a provision as a proposal ? )