''Being homosexual or bisexual is not a disease, it is not synonymous with perversity, nor does it constitute a crime,'' says the web site, which aims to ''overcome the taboos and prejudices that persist'' in Cuba.

Homosexuality ''is a sexual orientation that is not caused by seduction at any age, it is not contagious, and is not acquired by educational defects or negative examples in the family environment,'' says the CENESEX web page.

The Infomed web page, the most visited Cuban Internet portal with 150,000 hits per day, includes the graduation photos of a group of transsexual and transvestite sexual health promoters, a glossary and the emblematic rainbow flag.

The possibility for more visibility for an issue that has traditionally been silenced by the government-controlled media on the island began to take shape in the two years leading up to the 16th World Congress of Sexology, held in Havana in March 2003.

According to sexologist Mariela Castro, director of CENESEX, what is occurring ''is the result of an effort of more than 30 years, and now we are seeing its fruits more clearly.''

CENESEX emerged in 1989 out of the National Working Group on Sex Education, which was founded in 1972 by the Federation of Cuban Women, a non-governmental women's group.

Made up of experts and officials, the entity operates as an adviser to the permanent parliamentary commission on children, youth, and women's rights, with the mandate of creating and implementing the National Programme for Sex Education.

She says that 10 years ago it would have been nearly impossible to introduce a textbook on sex in the high schools. But such texts are being included in the curriculum now, and they include unprejudiced information on sexual diversity.

Nor would there have been such tolerance of training on transsexual and transvestite issues. ''In the 1960s, 70s and 80s, the resistance against even mentioning sexual diversity was incredibly strong even amongst that population,'' Castro told IPS.

With the advances of the past decade, she added, homosexuals, transvestites and transsexuals began to ''flourish with greater freedom, to have a public presence, to be everywhere.''

In her opinion,'' this presence has provoked opinions amongst the general population, for and against, but they are opinions, observations, concerns, reflections.''

''In this context, the CENESEX mission is to provide the elements for analysis that are necessary for defining appropriate policies that are coherent with our social project,'' said the sexologist.

Rejection of non-heterosexual expressions of sexuality remains widespread in Cuba, which experts see as being linked to the predominant culture's entrenched ''machismo'' and homophobia.

But studies show that gays, lesbians and even a broad segment of the heterosexual population say there is greater tolerance now than compared to the 1960s and 1970s.

Cuban legislation does not include homophobic-slanted regulations, but nor does it explicitly recognise the right to sexual diversity.

Although there have been some isolated cases of symbolic ceremonies uniting gay or lesbian couples, there have been no public demands for legalising homosexual marriage, the right to adopt or, for lesbians, the right to assisted fertilisation.

In Cuba there are no established gay or lesbian organisations, but in recent years groups have formed through the Health Ministry's national network of centres to prevent sexually transmitted disease and to fight HIV/AIDS.

The CENESEX Internet site is part of a broader project of the ministry, which includes a forum to promote reflection and debate about masculinity, relationships, sexual diversity and other issues.

The forum comprises specialists from different fields and plans to hold workshops on topics like current sex legislation in Cuba and the social perception of homosexuality.

It also disseminates the experiences of people the CENESEX experts have collected through their discussions on sexual diversity with various groups, such as university students, social workers and prisoners.

''We know it is a controversial issue and we know we are going to run into criticism,'' says Julio César González Pagés, professor at the University of Havana and coordinator of the forum administration.