Open End Mortgage
A mortgage permitting the mortgagor to borrow additional money under the same mortgage, with certain conditions.

Open Listing
An authorization given by a property owner to a real estate Broker wherein said Broker is given the nonexclusive right to secure a purchaser; open listings may be given to any number of Brokers without liability to compensate any except the one who first secures a buyer ready, willing and able to meet the terms of the listing, or secures the acceptance by the seller of a satisfactory offer.

Open Space   
Any land which has not had any significant buildings or structures erected on it. Most often used to describe desirable neighborhood features like parks.

Open Source
Software which is distributed with its source code such that developers can modify it as they see fit.

Organic Search Results
Most major search engines have results that consist of paid ads and unpaid listings. The unpaid / algorithmic listings are called the organic search results. Organic search results are organized by relevancy, which is largely determined based on linkage data, page content, usage data, and historical domain and trust related data.

Original Equity
The amount of cash a home buyer initially invests in the home.

Original Principal
The total amount of principal owed on a mortgage loan at the time of closing.

Owner Finanacing
A transaction where the property owner provides all or part of the financing.

Origination Fee
A fee or charge for work involved in the evaluation, preparation and submission of a proposed mortgage loan.

Outbound links
Links that direct "off-site" to another website.