Since I am Australian, I am only going to discuss the situation in Australia. I will leave it to other comrades to discuss their national efforts.
Australia's Socialist Groups and Their Activity
Australia has three socialist organisations of any note, the reformist Socialist Alliance, which has a parliamentary party which is has a presence in some electorates on the local level. Socialist Alternative which is Australia's principal revolutionary organisation of Trotskyist tradition, whose presence is most felt on university campuses and is primarily involved in student politics. And Solidarity which are by far the smallest of the three. Solidarity, to the best of my knowledge, has no effective strategy in place, and in my experience has often argued for petty-bourgeois (middle class) liberal efforts in the community despite claiming to be a revolutionary socialist organisation.
Outside of each organisations individual milieux, most of their social effort goes into building their organisations through recruitment and propaganda, and building demonstrations. Of the three, Socialist Alternative is by far the most successful on both fronts. Socialist Alternative has also been the principal organiser for much of the grass roots, non-union, action in Australia. Most notably the turn of the millennium demonstrations in solidarity with asylum seekers and more recently the marriage equality campaign (It was, in fact, Socialist Alternative who built the campaign, with assistance from university queer collectives. It was not until around 2010/2011 that larger, more liberal-style political groups became involved in principal organisation.), and solidarity campaigns with Palestinians (again, Socialist Alternative were principal organisers with the assistance of Palestinian / Arab community groups - though ultimately these campaigns have failed to maintain momentum due to the conservatism of the community leaders).
For the majority of socialists, whether they belong to an organisation or not, whether they are revolutionary or reformist, the principal positions they hold lie in grass roots politics, usually entrenched in trade unions and workplaces, rather than in parliamentary parties. Those who do invest their resources in parliamentary parties (such as Socialist Alliance) do so primarily because they lack significant grounding with the working class. In fact, I would argue that this lack of working class grounding is a negative influence on all three of the major socialist groups in my country for different reasons.
The Role of the Socialist
For the Marxists like myself the question of growth is not a question of growing the largest socialist party to dominate the political landscape. While having a cohesive, revolutionary, party is an important element to class struggle, it is not the be all and end all. What is far more important is the development of class consciousness which can only be had by drawing attention to the material conditions of capitalism. That is to say capitalism's foundations as an exploitative and oppressive political economy, its class antagonisms - between worker and capitalist, and the collective social and economic power of the working class.
The natural extension of this class consciousness is working class militancy - specifically industrial action, which has been a pivotal element of social upheaval the world over since the industrial revolution. As Socialists we point to that militant action as proof of worker's capacity to seize control of their own circumstances. We point to that militancy as the real agent of change.
For the revolutionary socialist, we reject wholeheartedly the proposition of change through reform. Rather, we identify working class collective action as the agent of those changes, and reform as little more than the concessional placation of the ruling class in its self-preservation. Furthermore, we wholly reject the proposition that parliament and reform are capable of changing the material foundations of capitalism and class society: the private ownership of the means of production.
The State of Marxism, and Revolutionary Socialists At Large
We are presently in a period of recovery. That is to say that with the fall of Stalinism and the discredit of Maoism, and the disintegration of the separatist politics of the 60s - 80s, we have been regrouping. Marxists, and socialists in general, particularly in the west are extremely few in number with equally few resources. We are no longer the collective force of the First International or the international Communist Parties (though most of them are markedly un-Marxist Stalinists or Maoists).
This period of rebuilding is slow, and it has largely happened during a broad recession of class consciousness and militant labour movements - owed to the onslaught of the right wing during the 80s, 90s and 00s in the west. However, as the global situation worsens, and crises continue to expose the naked truth of capitalism's political economy, the vigilance of socialists will pay off. More workers will unionise, or become sympathetic to the unions in a bid for better conditions. More attacks from capital will occur, pushing workers more and more toward that class awareness.
For the revolutionaries, we understand that it is not a straight line. We do not scramble for parliament in a desperate effort to remain relevant. We do not cut deals with the capitalists, or appeal to the sensibilities of the capitalist parliamentary system, as Sanders and other Social Democrats do. We hold true to the practice and theory of workers' self-emancipation. We keep their tradition alive. We test those politics daily, and when the time comes, when revolutionary fervour has come again, we make every effort to map the path forward.