The conflict, Africa's longest-running civil war, has left about two million people dead.
It ended with a peace accord in January 2005, opening up opportunities for development in one of the world's poorest regions.
International donors have pledged an estimated $4.5 million in aid for the region over the next three years, but are threatening to withhold development funds pending the resolution of the conflict in Darfur.
But the Arab League, anxious about the prospect of the break-up of a member state when southerners vote in a referendum at the end of a six-year interim period that started in July 2005, has been encouraging Arabs to assist.
Making unity attractive
The 22-member body says response has been negligible so far and only a handful have put money into an Arab League fund for south Sudan, earmarked for development projects directed at making "unity attractive" come referendum day.
But the Kuwaitis have announced the launch of three projects simultaneously in the south's central Equatoria state of Bahr al-Jabal.
Returning the love
When Saddam Hussein, the Iraqi president at the time, invaded Kuwait in 1990, Sudan's central government backed Baghdad, but former southern rebels offered to send soldiers to help liberate Kuwait from Iraqi occupation.
Maaz al-Fihayid, president of Sukait, the joint Kuwaiti-Sudanese company undertaking the investment, said: "By carrying out these projects and others under consideration, we are returning the love the people of the south have shown to the people and government of Kuwait.
"Unlike others, the late John Garang [who was leader of the rebel group, the Sudan People's Liberation Movement] condemned the Iraqi invasion of Kuwait."
On Saturday, Munzir al-Issa, the Kuwaiti ambassador in Khartoum, accompanied a delegation of Kuwaiti investors to Juba to inaugurate a $70 million project to upgrade the town's Nile river port.
They also inaugurated a five-star hotel project in Juba, expected to be the first in the region, at an estimated cost of $40 million, as well as a $10 million fisheries industry.
Salva Kiir, the president of south Sudan, told the Kuwaitis: "We are happy to note that Kuwait was the first country to have come in to assist the south after the end of the first civil war in 1972 and is now the first country to do the same after the end of the second civil war."
Kuwait was the only Arab country with a liaison office in Juba before the war through which it funded the construction of the only non-governmental housing estate in the town and the al-Sabah children's hospital.
The residents of Juba turned out in force on Saturday to attend the grand ceremony held to launch the projects and express gratitude to the business delegation headed by Maaz al-Fihayid, the president of Sukait, the joint Kuwaiti-Sudanese company undertaking the investment.
They greeted the Kuwaitis with songs and traditional dances.
Sukait said it expected the port project to be completed in two years to connect villages along the Nile and aid the repatriation of millions of people displaced by the war.
It said it would collect 95% of revenues from the project, launched on a Build Operate Transfer (BOT) basis, with the 5% going to host, Bahr al-Jabal state, which will take full control after 30 years.
Al-Fihayid said the hotel would be completed in 18 months. The fishing project would be ready in 10 months.
Clean water and electricity are virtually non-existent in much of the south, which has had no investments or business in decades to generate jobs for its people, most of whom live from hand to mouth.