The Romanian Socialist Party (Romanian: "Partidul Socialist Român" ) is a political party in Romania formed as the Socialist Alliance Party in 2003.
 It developed out of the wing of the Socialist Party of Labour (PSM) that objected to the merger of PSM with the Social Democratic Party in July 2003 and wanted PSM to continue to exist as a socialist party.
 Romanian authorities did not recognize this group as PSM, and instead it took the name PAS (Socialist Alliance Party).
 On 1 December 2013, the party decided to change its name to the Socialist Alternative Party.
 In 2015, it changed its name to the "Socialist Party of Romania".
 The unregistered Romanian Communist Party (present-day) had argued that PAS is a pseudo-communist party.
The Autonomous Socialist Party of Southern Jura (French: "Parti socialiste autonome du Sud du Jura, PSA-SJ, or PSA" ), is a Swiss francophone subcantonal political party in the Northern Bernese Jura district of the Canton of Bern, affiliated to the Jura Socialist Party, itself a component of the Swiss Socialist Party (SP/PS).
 It coexists with the Bernese Jura Socialist Party (PSJB), affiliated to the cantonal Bernese Socialist Party, also affiliated to the federal SP/PS.
 The PSA favors a unification of the French-speaking district of the Canton of Bern with the French-speaking Canton of Jura, while the PSJB opposes it.
The Socialist Party of Colorado was an affiliate of the Socialist Party of America, lasting from the first decade of the twentieth century to at least the 1950s.
 Later there was a Socialist Party of Colorado affiliated with the Socialist Party USA.
 The Socialist Party of Colorado engages in both electoral politics and non-electoral activism.
The Free Socialist Party/Marxist-Leninists (German: "Freie Sozialistische Partei/Marxisten-Leninisten" , abbreviated FSP or FSP/ML) was a small Maoist political party in West Germany.
 FSP/ML was the second Maoist group founded in West Germany.
 It was one of the predecessor organizations of the Communist Party of Germany/Marxists–Leninists.
Socialist Party Scotland is the Scottish affiliate of the worldwide Marxist and Trotskyist organisation the Committee for a Workers' International.
 Socialist Party Scotland is the sister party of the Socialist Party in England and Wales and the Socialist Party in Ireland.
 Socialist Party Scotland plays a leading role in the Trade Unionist and Socialist Coalition (TUSC) which standing ten candidates in Scotland at the 2015 general election.
 Four of the ten Scottish TUSC candidates are members of Socialist Party Scotland.
Mao Zedong Thought (), or Maoism, is a political theory derived from the teachings of the Chinese political leader Mao Zedong (1893–1976).
 Its followers are known as Maoists.
 Developed from the 1950s until the Deng Xiaoping reforms in the 1970s, it was widely applied as the guiding political and military ideology of the Communist Party of China (CPC), and as theory guiding revolutionary movements around the world.
 The essential difference between Maoism and other forms of Marxism is that Mao claimed that peasants should be the essential revolutionary class in China, because, contrary to their industrial working "comrades", they were more suited to establishing a successful revolution
The Socialist Party of Connecticut (SPCT) is a socialist political party in the U.S. state of Connecticut.
 Founded as an affiliate of the Socialist Party of America, the party split with the SPA in 1936 and joined the Social Democratic Federation.
 In 1957, the Social Democratic Federation reunified with the Socialist Party of America.
 In 1973, the SPA voted to reform and rename itself Social Democrats, USA, which sought to reform the Democratic Party.
 The current Socialist Party of Connecticut is the state chapter of the Socialist Party USA.
The Independent Socialist Party (Czech: "Neodvislá socialistická strana" ) was a political party in Czechoslovakia.
 The party was founded in March 1923.
 The party included a number of former anarchists, who had joined the Czech Socialist Party in 1918.
 They had however been expelled from the Czechoslovak Socialist Party in 1923, as they opposed the Defense of the Republic Act.
 In the Czechoslovak National Assembly, the Independent Socialists formed a joint parliamentary group (Socialist Association) together with the Independent Radical Social Democratic Party of V. Brodecký.
 The two groups were set to merge, but Brodecký's group decided to merge with the Czechoslovak Social Democratic Workers Party.
 The Independent Socialist Party took the name Independent Socialist Workers Party (Czech: "Neodvislá socialistická strana dělnická" ) at a congress in June 1924.
The Praja Socialist Party (PSP) is an Indian political party.
 It was founded when the Socialist Party, led by Jayprakash Narayan, Acharya Narendra Deva and Basawon Singh (Sinha), merged with the Kisan Mazdoor Praja Party led by J.B. Kripalani (former President of the Indian National Congress and a close associate of Jawaharlal Nehru).
 It led the cabinet under Pattom A. Thanu Pillai as chief minister of Travancore-Cochin from March 1954 to February 1955.
 A section led by Rammanohar Lohia broke from the party in 1955, resuming the name "Socialist Party".
 .
 It again came to power in the new state of Kerala under Pattom A. Thanu Pillai from February 1960 to September 1962.
 Another section of the party, led by the trade union leader George Fernandes, broke off to become the Samyukta Socialist Party in 1969.
 In 1960, Kripalani left the party and in 1964, Asoka Mehta joined Congress after his expulsion from the party.
 In 1972, a section merged with Fernandes' party to become the Socialist Party once more, before becoming part of the Janata coalition following the Emergency in 1977.
The Socialist Party of the United States of America (SPUSA), usually simplified as Socialist Party USA or Socialist Party, is a multi-tendency democratic socialist party in the United States.
 The SPUSA was founded in 1973 as a successor to the Socialist Party of America, which had been renamed Social Democrats, USA a year before.

Question: When was the The Free Socialist Party/Marxist-Leninists party developed?
Answer: 1950s