Civil war in action, or three countries in one. Projectvisa.com is treating it as three, as there are three different authorities patroling different borders.
Everyone needs a visa, or you may be able get one at the border.
Whatever the situation it would be best to get one before arriving (if you can), and save yourself some bribe money. Visas are straightforward and cost around US$50
Somalia is split into three main areas;
1. - Somaliland - In the north near Djibouti.
To get a visa for Somaliland you will have to contact one of the Somaliland missions and apply. Visas are no longer available at the border or airport.
2. - Puntland - is south of Somaliland and north of Mogadishu. You can get a visa on arrival at the airport.
3. - Somalia now requires you to have a visa before you arrive at the airport. If you are visiting as a tourist or on business it is recommended that you have someone meet you at the airport/border.