Open Source
Open source refers to software which is freely distributed with its source code so developers can modify it as they see fit.

Optimization
Making a website search engine and user friendly.

Organic Listing(s)
Websites which appear on search engine results pages for free and are not sponsored or paid for.

Organic Search Marketing
This is the same thing as search engine optimization and/or SEO.

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 by linkage data, page content, usage data, and historical domain and trust related data. Some studies have shown that 60 to 80% + of clicks are on organic search results.

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