com-unism means "to unite" that all people on the planet must be brothers rather than consider each other as rivals and tools to make wealth. [...]
Is it right to consider the[sic] communism as such a broad category? (not just as dogmatic Marxsim?)
No. Dictionary definitions are not appropriate theoretical categories in social science.
Engels discusses Robert Owen's social thought as "Communism" extensively at the end of part I of Socialism, Utopian and Scientific. The definition Engels provides at the end of the book is useful, chiefly for denoting some of the high points of the most commonly used definition of communism: the society that results from common democratic ownership of the industrially productive tools of society by society.
In this sense communism requires:
- Advanced productivity. Discussions of utopian agricultural communes in the United States or post-Anabaptist communal economic endeavour isn't really appropriate.
- Holding of productive property in common. Being part of a fruit-and-veggie coop where someone ensures everyone gets half a head of cauliflower out of the weekly buy isn't relevant. Common property in a market garden is.
- That property being democratically controlled: the common property must be substantively not merely formally common. I'm a member of plenty of mutual societies in capitalism; but, I can't exercise effective control, alongside others, of these mutuals for various reasons. A corrupted Rochester coop isn't worth considering.
- That this nature of economic relations be society wide. It is not reasonable to consider as communism a society where, for example, the production of shoes is common; but, media is owned by capital.
How to determine if movement falls into the category of Communism or not?
Any movement that advocates for an advanced productivity society, where property is held in common should be considered a communist movement.
Sadly this means that many, if not most, "Communist" parties have in fact been non-communist movements.
Personally, I view the immediacy of achieving communism in an organisation's behaviour as an important part in whether an organisation is communist or not. The Fabian Society, for example, viewed the possibility of achieving communism as an eventual thing. (I am too too selfish to be bothered with the "eventual" rather than the "actual.") If someone believes in something, and advocates for it, but acts as if it isn't going to happen that doesn't seem like belief or advocacy to me.
Similarly, I don't trust organisations with pure and utopian plans for the universal reorganisation of society on the model which our glorious leader has discovered (see again Engels, Socialism, Utopian and Scientific here). My experience and reading of "pre-figurative forms," of moments when communist behaviour appeared in my life, or in historical records, strongly indicates that there's more genius in the working class as a whole, than in any particular worker. I don't trust utopians with grand plans. This is, however, because I'm a historical materialist.
In what way does Zeitgest[sic] differ from Communism? (might be the anarchist branch of it)
No, the anarchist branch of communism is anarchism. You might want to start with Proudhon, Bakunin (whose conflicts with Marx in the First International were fraught), Kropotkin, Makhno, Malatesta. I'd recommend George Woodcock's Anarchism : A History Of Libertarian Ideas And Movements.
If we can take this document: http://thezeitgeistmovement.com/orientation#faq5 as a reasonable discussion of Zeitgeist's beliefs you'll notice in the section 'The “Prima Facie” Fallacy' that this particular branch of Zeitgeist argues directly for a technocratic and anti-democratic control over production; as opposed to the humanism that the collective author claims to see in Marxist communism.
Honestly, Zeitgeist claims to be, and appears to me, to be an inheritor of the Technocratic movement. It is not communist because it does not advocate for a society where the commonweal is the commonwealth: Zeitgeist advocates for a technocratic class society.
Why cannot we say that J.Fresco is a communist and promotes the communism?
Because J. Fresco does not want goods or production held in common. He appears to want production and distribution controlled by "science." (See the previously cited faq). My understanding of critiques of technocratic "new classes" are that this kind of class society would be, and potentially has been (in the "soviet-style" societies) an inhuman monstrosity like all previous class society where one class claimed control over the social product or the socially productive forces.
Engels praises Robert Owen for overcoming his technocratic impulse:
From 1800 to 1829, [Robert Owen] directed the great cotton mill at New Lanark, in Scotland, as managing partner, along the same lines, but with greater freedom of action and with a success that made him a European reputation. A population, originally consisting of the most diverse and, for the most part, very demoralized elements, a population that gradually grew to 2,500, he turned into a model colony, in which drunkenness, police, magistrates, lawsuits, poor laws, charity, were unknown. And all this simply by placing the people in conditions worthy of human beings, and especially by carefully bringing up the rising generation. He was the founder of infant schools, and introduced them first at New Lanark. At the age of two the children came to school, where they enjoyed themselves so much that they could scarcely be got home again. Whilst his competitors worked their people thirteen or fourteen hours a day, in New Lanark the working-day was only ten and a half hours. When a crisis in cotton stopped work for four months, his workers received their full wages all the time. And with all this the business more than doubled in value, and to the last yielded large profits to its proprietors.
In spite of all this, Owen was not content. The existence which he secured for his workers was, in his eyes, still far from being worthy of human beings. "The people were slaves at my mercy." The relatively favorable conditions in which he had placed them were still far from allowing a rational development of the character and of the intellect in all directions, much less of the free exercise of all their faculties. [Cited in Engels as From "The Revolution in Mind and Practice," p. 21]
Owen knew that to direct another's labour is to make them your slave. I see no difference when the director is "science" or rather, and of course, "scientists."