Lightning.out is now available in winter 16,
Assume your VF page is as follows, you can user $Lightning.use() and $Lightning.createComponent() in order to call the component
<apex:page standardController="Account" showHeader="false" sidebar="false" showQuickActionVfHeader="false">
<apex:includeScript value="/lightning/lightning.out.js" />
<apex:stylesheet value="/resource/slds0120/assets/styles/salesforce-lightning-design-system-vf.css"/>
<apex:includeLightning />
<div class="slds" >
<div id="lightning" />
</div>
<apex:includeScript value="/canvas/sdk/js/publisher.js" />
<script>
var accountId = "{!$CurrentPage.parameters.id}";
$Lightning.use("c:AccountDetails", function() {
$Lightning.createComponent("c:UpdateAccountDetails",
{ "accountId" : accountId },
"lightning",
function(cmp) {
});
});
</script>
</apex:page>
AccountDetails is the component which extends ltng:outApp, Please see the below code for the application.
<Aura:application access="GLOBAL" extends="ltng:outApp">
<Aura:dependency resource="c:UpdateAccountDetails" />
</Aura:application>
UpdateAccountDetails is my component,which I'm not going to include the entire code here (Contollers, helpers etc.)
<aura:component controller="UpdateAccountDetailsController" >
<aura:handler name="init" value="{!this}" action="{!c.doInit}" />
<aura:attribute name="account" type="Account" required="true" />
<aura:attribute name="accountId" type="String" required="true"/>
<--More code-->
<div aura:id="backdropDiv" class="slds-modal-backdrop slds-modal-backdrop--closed"></div>
<!-- /div -->
</aura:component>
Please note you do not need to have a My Domain in order to call this component inside a VF page